Here's a very easy way to play in 7, but throw in an even "crosscurrent" of 4 even beats. The places where the "4" lay into the 7 are the following: The One, Ah of 2, & of 4 and e of 6.

4 against seven

I took a picture of the blackboard at my rehearsal facility where I explore my inner rhythmic proclivities, and a drummer Jeff Wald from just outside Nashville, TN took the liberty of demonstrating it. (Thanks Jeff!!)

Here's another breakdown of it. I put into Superscript "K" for kick and "S" for snare on the parts of the beat that are bolded, and anything with a parenthesis around is to be counted and not played. You can see the K S K S (1 2 3 4) progression within the 7 part, which is the hi-hat (1e& 2e& etc...) The beats in 7 are underlined.

||:1K e & (a)   2 e & aS   3 e & (a)   4 e &K (a)   5 e & (a)   6 eS & (a)   7 e & (a)   :||