one thing you can try is pan your overheads where you want them and then listen to just the overheads. Then you pan your drums in the corresponding position of where they are in the overheads. For example I'll listen to the over heads, then un mute the high hat and try and find out where I heard it in just the OH mics. If i need to i'll mute the HH and listen again until I find it. I find this will give you an image of the entire kit as if you were listening from the OH perspective, which is in stereo (and probably the ONLY stereo representation of the actual kit).