You've got a few things that are working against you IMO. First why use different rooms? Are either room acoustically treated to be as neutral as possible? If neither is, then pick one and treat it. Seriously. That will go way further than anything else you can do. Which one and how to treat is impossible for me to answer. There are other great forums and resources on that subject. Check out some books by F. Alton Everest also.
Then understanding what you're doing matters too. Read up on bit-depth and sample rates. What they mean, how they affect sound, and what works when. But fwiw I always track in 24-bit. Mix in either 24-bit or 32-bit float. Master in whatever bit depth I mixed in. And then dither down to whatever you need the final file in. And use sample rate conversion if necessary at that point.
But seriously get you a room treated so you can hear the subtleties of the difference in 96khz vs 48khz sample rates. Or 1.5 db of gain at 1.6khz vs 2.5 db at 1.8. Or a compressor set at a 2:1 or 4:1 ratio. Once you can hear better your mixes will translate much better.
I don't mean to sound crass. But there's a reason the guys that do it for a living are called engineers. And no I'm not one that can say that. There's a lot of technical info that gets mixed with artistic choices to record/mix/master music. It's still a hobby mostly for me. But one I'm def addicted too.
