Perhaps signature campaigns are a good way, they are not difficult for beginners, and also may help the experienced users.
It's true but there are not many options for low-rank members and nowadays there are not much signature campaigns going on as it used to about a year ago.
You are right about this but you can than first try to get your account to a higher rank, a lot of people did this first and than did campaigns.
Signature campaigns are very profitable if you have the good rank for it and also a good campaign.