DOM + 2C-B: Great mix, very good euphoria. Take the 2C-B maybe 1-2 hours after the DOM and the durations line up more or less perfectly. Not too much body energy, and some of the best music enhancement I've had. Highly recommended, if you happen to be lucky enough to get a hold of both of these. 8 mg DOM + 25 mg 2C-B = perfect
DOM + 2C-I: I myself haven't tried this but know of a couple of people who have, and they seemed to agree that it had good visuals, but the body component was not worth it overall.
2C-I + 2C-E: I've tried this on two occasions, once at 16 mg 2C-E and 20 mg 2C-I, the other time at 20 mg each, although I had tolerance that time from doing 2C-I two days earlier. Excellent combo, one of my favourites. These two synergise very nicely. So nicely in fact, that I much prefer it to taking 2C-E alone, and since I happen to have an abundance of 2C-I I can't see myself taking 2C-E by itself any time in the near future. Neither gets in the way of each other, and they both add up to amazing visuals and a very psychedelic headspace, but one that doesn't feel terribly "out of control", either.
2C-T-21 + 2C-I: A waste. I took the 2C-I maybe four hours into the 2C-T-21 looking to push it up a bit, but it just completely overpowered it.
LSD + 2C-I: 2 hits LSD and an hour later, 16 mg 2C-I. Good experience, one I'd be willing to repeat. The muscle tension was a little annoying, but I had a lot of control over my visuals which was really nice. Not in the sense of "creating" what I wanted to see, but I could move them around my field of vision. At one point I remember I was trying to pack another bowl but there was a lot of "noise" in the way, and I was able to push it out of the way so I could see the bowl I was packing. That was a good moment.
LSD + 2C-B: Compared to when mixed with 2C-I, better visuals and easier on the body, but less euphoria, and the 2C-I contributed to the psychedelic headspace much more than 2C-B did. Overall, I like it more with 2C-I I think, but this is a very good combo as well.