Several years ago I decided it would be fun to try raising queens. My first cells were not very impressive, but I got the hang of it pretty quickly. Occasionally there is still a graft that fails, but nothing is 100% I suppose.
When I first started with mating nucs, I thought it was important to arrange the nucs in distinctive ways that would make it easier for the virgin queens to find the right home on the way back from their midair mating flights. It turned out that they know their way back home better than I ever would have guessed. Last year I had extra full-size equipment, and I got a good mating percentage on 4-way pallets sitting close together (about 80% as I recall).
Normally I do not use full-size equipment. We have a number of 4-frame nucs that I usually use. Here you can see that the two outside nucs have their entrances facing one direction, and the middle nuc is flipped around to face the other way.
I keep a few lines of nucs that were started on different batches of cells. I often mix around the different colors of nucs, but I don't find that it makes much difference in practice.
Here's a line that is all light green.
I'm not doing this on a grand scale, but it's useful to have queens on hand. It's also fun to ship them around the country--it's one of those interesting activities that never entered my mind for years and years.