I don't have high commission traffic, but I've been commissioned a fair few times over the course of several years.
First, I'd start with figuring out your terms of service (ToS)/prices, if you need ideas mine are on my blog. As the other person that has responded to you so far has said, adjust prices according to demand (that comes with time though. Just pick what you think would be a fair cost for now!). Once you've got your ToS and prices sorted, personally I've had the most commissioners come to me via discord. Advertise in discord servers (in whichever channel they have dedicated to advertising comms) and anywhere else you're active, people will eventually come to you ^^
Also a mistake I used to make quite often was choosing to be friendly over being professional. Don't be stone hearted towards your clients of course, but also don't let your will be bent and do stuff like sending the fully finished piece with no watermarks or anything before you've received a full payment. Unless your client is a close friend, always prioritise the safety of yourself and your artwork first.
As a last tidbit, if you want to go the extra mile (but keep in mind you don't have to! Plenty of artists don't!), have a little "portfolio" of sorts for clients to take a peak at before choosing to commission you. For example, I use my Toyhouse. It has some info abt me, links to all of my art service ToS and price sheets, and all of my characters are on there for others to peruse and get a feel for my artstyle. Again this is purely optional though, I just have this for convenience. Trello is another thing I've seen other artists use- it's a website where you have little categories that you label and you move stuff along those categories so clients can see what stage their commission is at without having to bug you (shit explanation but it'll make sense if you look it up. The categories in question can be stuff like "waiting list", "started", "in progress", "near complete", "awaiting final/full payment", etc). I don't use it personally but it is pretty neat from what I've seen. Play around and see what works for you!
I hope this has been of some help :3 all the best!!