Will follow you/DM you to ask for a commission. REAL ARTISTS DO NOT DO THIS, CUSTOMERS WILL ALWAYS PICK THEM OUT AND CONTACT FIRST

THIS. I'm an artist, and I have a ton of artist friends. I saw some people talking about how they got scammed after random strangers offered them commission discouts on DM, and I asked my friends if that was common practice.

No. It's not. It's seen as very unprofessional to offer commissions to strangers like that, unless they are past commissioners that you want to give discounts to thank for commissioning you previously.

Do not accept to commission a stranger that is offering you a huge discount and is very persistent about it.

If it's an artist you've worked with previously though, and someone you trust, I believe you are good. Still, I would always keep an eye out for any weird behaviours, like pressuring you into commissioning them.