Mostly a reader, rarely post, so here is what I look at before signing up anywhere. After a few bad experiences I stopped trusting the big banners.
First thing is the licence: find the licence number and look it up, and if your country is on the allowed list. Then payments: I want at least one fast e-wallet option, and cashout times should be listed up front.
Bonuses are the tricky part. Read the wagering and the max bet rule, and live tables often do not count at all. A useful overview with bonus rules, app info and payment methods is worth a read here [url=http://weblabor.hu/tagok/122099]craybet[/url] so you know what you are signing up for.
On mobile I mostly use the browser version, and a good site loads fast and does not log you out every five minutes. Support matters too: if they answer in a couple of minutes that is a good sign.
Hope this helps someone. Treat it as entertainment, not income.