The cross press up is just a press up with a side twist, it seems to make a nice combo. The way I work it is I do one press up and twist to one side(keep knee straight and pull your navel in), then do two press ups and one twist to the opposite side, then three press ups and twist to the opposite side.
|You can have fun to and work on your balance|
I go up to ten press ups and then another 10 again and come back down, total 110 press ups and twenty side twits. You get a rest from the press ups in the twist, so you are able to do big set fairly comfortably, and the twists stimulate a lot of core.
I like these a lot, and you can concentrate on form more than just banging out a lot of press ups, and remember to breathe.
At the moment I am doing lots of days on, so not following a very rational based training thingy, so occasionally I do a few sets of pull ups, and a couple of cross press ups sets, or I might combine a few cross press ups in my yoga. In the old days I would have kept a weight belt on, but this can lead to back pain if you don't watch it, if you do watch it, it can lead to a really high level of strength....
|Or you can do a yoga front platform with Agni Pran for 3 minutes(breath of fire if you are familiar with this Pranayama)|
Good luck and have more fun and success....