Good question. There isn't a way that's most effective AND easiest.
Here are some factors that will make you more effective ClickBank vendor or affiliate. But these are not the easiest.
1. Find a very niche market
2. Find what they want
3. Create a highly niche product to meet that need
4. Get a domain name that contains key words for that niche
5. Create your website using copy that appeals to that need. Use as many keywords as possible in that copy.
6. Use social media, article marketing and backlinks to drive traffic to your copy
7. Sit back and be patient.
There are more marketing tips on my website: http://www.mindstrategist.com
Hope this helps.