This question isn't particularly clear, but the advice I can give is that visas are more likely to be issued to people who have clear travel plans and are more likely to be denied to those who cannot state a clear premise for their trip. Your entire visa application is evaluated around the purpose of your trip, and stating it clearly will help the officers determine whether your application should be granted.
Here, it doesn't sound like you have clear plans at all. You want an entirely open itinerary with multiple visits of some undefined length. Your premise boils down to "I want to visit Europe some number of times and have not decided anything more" instead of a clearly organized itinerary. That's not good. So make a plan. Lay out exactly where you will go, how many days you'll stay at each location, where you'll stay each night, etc...
And the beautiful thing is that, once you have your visa and are inside the Schengen area, you can change your plans as long as long as your total stay is not more than the number of days printed on your visa. To facilitate this, as Burhan Khalid suggests, you can make fully refundable hotel reservations (check the fine print carefully, but many reservations are cancellable with 1-3 days notice, not all are). This is also a good idea so you are not forced to pay for hotels you cannot use if your visa is denied.
As noted in your last question: "lying on a visa application is grounds to annul a visa." If you apply for a visa with a well-defined itinerary and then show up at the border looking to do something entirely different, that could be a serious problem if they start asking questions. But if you come up with a solid itinerary and then decide to deviate during your trip, that's perfectly normal as long as you leave on time.