Long time lurker here, so here is how I pick an online casino these days. After a few bad experiences I stopped going by ads alone.
I always start with licensing: find the licence number and look it up, because some sites quietly block certain regions. Next come deposits and withdrawals: I want at least one fast e-wallet option, and cashout times should be listed up front.
The welcome offer is where most people get caught. Wagering of 35x or 40x is normal, and live tables often do not count at all. A useful overview with bonus rules, app info and payment methods is here bonus su Slotshopper and it saved me some time.
Most of my sessions are on mobile, so I check how the lobby works on a small screen. Test the live chat before depositing: if they answer in a couple of minutes that is a good sign.
Hope this helps someone. Set a budget and stick to it.