First you have to have some kind of business plan. Your find a keyword find a product approach is doomed to failure. Why would anyone buy from you a product? Why would you sell a product you knew nothing about just because you saw it on Clickbank. What can you offer a consumer/customer? If you think you are going to just go to clickbank find some high paying product, throw up some adwords ads and cash in... Well that's flawed thinking. The people who are sucessful marketing clickbank products are a light year ahead of you. They know how to find keywords, they know how to MARKET the product, write effective landing pages, etc. etc. So your problem is not finding a product or keywords. Your problem is developing a marketing stragegy and following your strategy. You would be well served to read everything Google has published on Adwords. Then find some products on clickbank. Then search for those products and see how others are marketing them. It's not a game. It's a business. The score is kept in dollars. It's not something you just decide to do one day - hit and miss
It's all about experience. Internet marketing is like a job. First you earn almost nothing, but you get experience. A bit later you start earning more, but for the same amount of time. You are not going to make millions in your first month of Clickbank+Adwords. You have to waste money and time to learn. That's the way how you get experience. And believe me, if you keep doing something and you really want to success, of course you will fail, sometimes you will win, but one day you will start making serious money and you will be happy that you didn't stop. All I want to say, that nothing is easy, and if you want to success, you have to work hard.