1. Avoid tail up slope landing at all times if you can. Though you might do so successfully, you increase the difficulty of handling for take off. The easiest situation I have found to be, when doing this is when there is a substantial head wind - with the tail up slope and within limitations. This is pertinent specifically for the take off and will allow you to ensure a positive forward cyclic positioning without the half-assed lurch skywards that would otherwise result. [Leaning into the wind]
2. If there is no other possible alternative - and lets face it [as another has already pointed out] that will be a very rare occasion warranting the consideration of whether it is wise to land there at all - then use the cross slope variation - within limits.
Your experience is by your own admission limited so my sincere advice is before attempting anything other than a landing on a flat surface 'in the field' practise in a known environment.
An aid to difficult landings on uneven surface is to be able to accomplish what I call a three point landing/take off - to/from low hover IGE. I found this to be a neat trick with aircraft that have a rotating undercarriage.
Best Wishes
Ace