Log into your favorite affiliate networks each morning and check for new offers. Look for offers with no restrictions first, as they are the easiest to set up.
Many offers state you must use your own landers, or there's no bidding on company names, trademarks, etc. Offers with no restrictions let you bid on their company name, brand name and generic product category.
And if permitted, bid on their domain name too, but in a variety of ways. Bid on it with and without the www, spaces in-between the .com and www all the variations you can think of.
Some merchants want to approve your landing pages. Be careful with that. You are giving them intel and design for free.
If your advertising campaign works, some merchants will copy it and close the affiliate program. Not all of them spy and steal, but it's happened often enough that I no longer work with merchants that must approve my landers.
Besides, if they need to approve it, you're suddenly catering to their design whims. The person doing the approving could be boss's nephew with zero experience at converting prospects into customers.
Check other networks for the same offer. New products and services often list themselves with several CPA networks. You may find that one network has restrictions on how you can advertise, whereas the next one may have no restrictions at all. That's why it's a good idea to join several, even if you don't use all of them equally.
If possible, you want to be the first person to test every new offer. Get the ads up right away, because if you snag first place in the WADS, the competition needs to bid more, or get a better quality metric, to knock you out of first place, which isn't an easy thing to do.
The secret to success? Find out where the people are going and try get there first.