Long time lurker here, so here is what I look at before signing up anywhere. After getting burned once or twice I stopped trusting the big banners.
Licence comes first for me: see which authority is listed in the footer, and if your country is on the allowed list. Then payments: I want at least one fast e-wallet option, and the withdrawal limits need to be written clearly.
Bonuses are the tricky part. Read the wagering and the max bet rule, and some games count less towards it. A decent independent write-up with the current terms is here [url=https://joy.link/cryptoplaypicks33d7#reveryplay-uk]revery play casino[/url] so you know what you are signing up for.
On mobile I mostly use the browser version, 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.
That is about it. Only play with money you can afford to lose.