I'd say your best bet is to post a rough outline of what you need doing here on the forums and see what responses you get.
Make sure to cover a few of the basic things an artist would need to know, such as: -
- What models you require (eg. I need a male head and a female head).
- Visual style you're aiming for (eg. It needs to be PBR / Voxel / Handpainted / Lowpoly / look like XYZ game - references or example images can be really helpful here).
- Any important technical requirements (eg. It has to work on really old mobile phones so needs to be 1k triangles)
- Timeframe for the work (eg. I need this by tomorrow / next month / no real rush).
- Paid or not paid (No need to be specific about rates / amounts in public, but it's important to be clear)
These are the basic type of things an artist would be looking at when considering a job. No need to go into all the details, that's something you can hash out with any interested parties.
You can also contact artists directly if you find someone you think could do what you need (maybe they have similar style stuff on their profile), but they'd still want to know the basics above, so why not a bit of both!
Hope that was at least a little helpful