I've been planning a trip to turkey for this July.
How easy would it be to avoid the areas where people are demonstrating?
If I hadn't already booked my flights, I would probably postpone the trip or go somewhere else. Since the tickets are non-refundable, I think I have to use them.
You should consult your country's travel advisories. All countries maintain such advisories, usually the state department is responsible for them. For example here is Canada's advisory on Turkey. Currently they are not advising against travel, just urging people to be cautious. Similarly the US advisory does not advice against travel but does admonish travelers to avoid any demonstrations.
So, as things stand it is probably safe enough as long as you avoid any demonstrations and keep up with the local news. It is worth keeping an eye on these advisories. If they begin to advice against travel you may be able to have the airline refund your tickets or change them. I had a flight to Thailand booked back in 2010 when they had some riots, the airline (Air Asia) allowed me to change my destination, at no cost, to Malaysia.
Demonstrations take place at Taksim square, which is a very small part of the numerous sightseeing of Istanbul. The historic center should be safe.
Moreover, if you plan to visit other places, you should see no demonstration at all, except in very localized spots in Ankara.
Demonstrations are nearly over in Turkey. Some demonstrations still happens, but for protesting the police who killed demonstrators. Since police do not interfere to the demonstrators due to previous police brutality events, nearly no clashes happen.
You can also get information from local citizens about the protests since all are previously planned demonstrations now. Since demonstrations take place in Taksim Square, you probably have no trouble while you keep away from Taksim Square while there are planned demonstrations in there.
İstiklal Avenue will probably be one of the places you wish to visit in İstanbul. It is close to Taksim Square, but since it is really crowded, you probably will not have any problem about demonstrations in there. But still, it is a better idea to go there when there is no demonstration in Taksim.
Beside all these, places that demonstrations took place is only a very small part of İstanbul, and not close to places you will visit in İstanbul.
Like İstanbul, there are a few important points for demonstrations in Ankara. By keeping yourself away from these sites while (previously planned) demonstrations took place would be enough.
Keeping these in mind, I guess you will have no problem in your trip to Turkey.
