First thing you need to do is to select a niche you are interested to work in, I know not every niche is for everyone, so choose the niche in which you have got more interest. If you are looking for ever green niches, then you can consider Weight loss, fitness, Diabetes as ever green niches, off courses there are many more in the list.
High Gravity, it means people are interested in that product and it’s high on demand. For some people, products with lower gravity do works as well, but if you are starting out, only consider the high gravity products. However, in any situation, the gravity under 20 is a ‘NO GO area’
Product price should be under $100 if it’s your first product you are promoting from clickbank. Not only it will be easier to sell but it will motivate you to for further sales. Products having $500 seems a lot more profit but at the same time, they are much harder to promote.
Have a deep look on video and sales page, if you are not convinced, you will not be able to convince someone.