You have a whole soundstage of 180° in front of you. Middle and to the edges are NOT your only choices. And while stereo can be nice, it is far from necessary.
What you need to do is look at the mix in total and find a good overall balance. What other instruments are there, and what is each instrument's part in the arrangement/mix? Then build a balanced soundstage around that, using more than just LCR (Left, Center, Right) panning.
General 4D principles here, apply only as required:
- in general you'll want to pan the skins to a side (not all the way) opposite of another instrument with similar arrangement density that has similar frequency forments or timbre. Try to balance your frequencies left and right as well as you density.
- in general, if the instrument is playing counterpoint to or sharing lead with another instrument or main vocal, try panning them opposite and just a bit off center from each other. For example, if the vocals are calling and the bongos are responding or filling to the vocals, pan the vocals maybe 15%-25% (give or take) one way and the bongos 15%-25% the other.
- if it's a very thin mix with a lot of space and not a lot of instruments or density, try panning the bongos 25-50% (give or take) one way, and a wet reverb of that track the same amount the other way.
G.