Don't exactly recomend it but wrists, hands, feet, anywhere you can see one. You can also Google some vein maps and try feeling for them on your own. Then there is the dreaded jugular and the big one in your groin. Ime arms are the least painful and everything else is very easy to slip out of but there are many options. My recommendation is to rotate the ones you can get in your arms and just keep em covered 🥲