How to avoid UK standard visa refusal?
The immediate and foremost strategy to ensure success is to instruct a UK solicitor with a practice area in immigration and visas. They can prepare an application for even the most awkward cases because they communicate with compelling language. They will usually have a web site listing their credentials, a good example being this page. You can then search on them to see where they have made public appearances or written significant articles. ECO's are glad when they see a cover letter from a trusted name because they know the application has been prepared to an impeccably high standard and they don't have to spend a lot of time on it (sometimes they read the solicitor's cover letter and then click the 'approve' button).
To get started finding a solicitor, the Immigration Law Practitioner's Association , which is their trade association, provides a customised search engine. You can also use their site to get relevant briefings. It's also a valuable internet resource for keeping up-to-date on specific situations.
You will not qualify for free legal aid, and those types of solicitors get fees for their services that can be breathtaking, we're talking GBP 2k - GBP 5k for a visit visa. On the plus side, they like really complex casework. So during the initial phase when you talk to them, they may decide that your circumstances are too easy and they won't take you on. It seems crazy that a lawyer would turn away work, but things work like that; they will not take you on if your case is too simple.
You can also search for regulated advisers in the UK. They are also viable practitioners that maintain an internet presence listing their credentials, like this example. When you find one you like, you can visit the Commissioners site to see their practice areas and to assure that they have a license.
Similarly you will not qualify for free legal aid, and their fees for a visit visa will range from GBP 500 - 2k. These practitioners will also avoid taking you on if they think your case is straight-forward. Doing things like that can cause reputation damage. If you have a clean history and there are no problems where expertise is needed they will point you to the Visa4UK site.
While you can always use an agent outside of the UK, remember that the UK regulatory sphere does not reach international practitioners and lots of agents (particularly in South Asia and Africa) are scam artists whose only qualification is that they are cheaply accessible.
If you decide that professional assistance is not appropriate for you, you can take an orderly approach to prepare an application yourself using first principles.
Read the rules. These were drafted with language meant to be accessible by anyone with a working knowledge of English. They have been hammered out over a long time so as to reduce ambiguity.
Read the guidance. This is a document that explains how to support your application by providing evidence. You should also avoid guidance that does not pertain to visitors. Lots of problems occur because people tried to use guidance (or forum advice) that were not relevant to them. Remember that specific issues like how to demonstrate strong ties to your country are invariably solved by adducing high quality evidence, and refusals are invariably rooted in poor quality evidence. It's all out there for people who study the guidance and provide high quality documents.
Read the ECO's guidance: This is a book published on the net that shows what the decision-maker will be looking for.
Make a itemized list of your supporting documents. Make it look really professional with the item name and why you are including it. Lawyers will do this for you to polish your application, but if you are applying by yourself it's critically important for the following reason...
Most of the time you will need to report to a Visa Facilitation Centre to enrol your biometrics and submit your application. Tragically, some of the VFS personnel have nurtured the delusion that they are practitioners and they will discard evidence that they think is irrelevant. We see footprints of this when somebody writes "They totally ignored my mother-in-law's property deed!" or "They said I did not submit my invitation letter, but it was on the top of my pile of stuff!" Lots of times the ECO never saw it because somebody in the pipeline decided it was irrelevant and discarded it or did not log it in Proviso. If a VFS person starts to discard your stuff, you should protest in the most emphatic terms.
- If you want to go for real overkill, you can read the Chief Inspector's reports. I like the Chief and read his stuff religiously.
Getting advice on the net: There are tons of forums and sites where you can ask a question (this is one of them in fact). Be sure that the answers you get are on target. You can see cases where somebody applying as a student got advice from somebody who applied as a spouse. Many of the questions we get here are ambiguous or omit fundamentally important information. Be careful and always consider the source. If you do decide to use the net, you can check here to see the sites sending the most traffic to the UKVI site. These are official stats...
More about advice on the net: There are some bottom feeders who search forums and offer their services. Remember that reputable solicitors and advisers in the UK do post in forums and do not participate in discussion groups. It's not the done thing. It damages their reputation. Also avoid dodgy advisers in South Asia, Africa, and the Pacific Rim. In some cases these 'advisers' will pocket the fee and send you a forged refusal letter a few weeks later. Some have the audacity to collect a fee for representing you at appeal and then send you a forged dismissal letter. It's a cut-throat market.
Even more about getting advice on the net: if you are filling out your application and reach a point where you are unsure what to put down and you want to put your question on the net, be sure to include vital information: your nationality, your visit premise, your consulate, and why you are unsure about what to put down. If you are asking a question like "should I tell them about my family in the UK?" or "I got a new passport, should I tell them I have prior refusals?" or "my uncle in the UK is irrelevant to my application do I have to write it down", then read the declaration on the last page of the application form.
Post-submission anxiety and remorse: Lots of first-time applicants submit their application and then start researching the net to see if they did it right or not. This leads to anxiety and the person will start to wallpaper the net with questions. Avoid finding yourself in this position by researching before you submit your application. Anxiety is part of the experience, learn to enjoy it. You can use UKVI's site statistics to get an idea of the turn-around time for your country.
Disclaimer: this answer contains links to fee earning individuals and organisation who are arguably recognized as best of breed. I have personal and professional relationships with them (it is unavoidable for me), but I receive nothing for linking to them or using their sites for indicative purposes.
You wrote that you are in Egypt. There's some general information about the British visa issuing post here that might also be helpful when you make your application. And I have personally (in the past) represented Egyptian applicants who were successful obtaining their visas from the Cairo post. It's not as hard as it seems if you read the materials before applying.