CPA a Newbie question

Hi guys,

2 newbies questions:

1) What is your resoning , regarding choosing an offer from your affiliate list..how do you choose generally choose it ?
2) How do you test an offer to see if it is worth persisting on it..is it efficient sending direct traffic in order to test it at the beggining or.. which testing method are you currently using/ do you suggest ?

Pro Marketer always try to use his/her own lander. I mean, they build their own way to promote. They rely on Split Testing, not on any specific/blind methods.