Well I would say deep is prob better, but only for getting the spermy further along , but there are lots of other things you can do to help, I really believe popping a cushing under your bottom imed after and legs in the air or resting against wall really helps for at least 30 mins, gravity is as useful and the deep thing!
You could also try that sperm freindly lubricant the girls in TTC have been going on about as that makes the path of the sperm really easy to swim through
Good luck TTC X