Have a good look through 'rock or alpine gardens images' to see what you like and what makes you cringe. A bad rockery is really bad - you'll know your own style. There are so many examples to see online, just to give you a base line to start from.
I like a naturalistic rock garden, where the rock placement mimics what you would find in the wild. A mound of stones, or a pile of soil with a few rocks spread over the top looks fairly awful to my mind.
Use a soil:grit ratio of 1:1, as a rock garden needs to be well drained, especially in winter.
When you place your rocks, make sure you leave crevices which can be planted up and backfilled.
If your rock garden is to be quite large then tiny alpines will be lost, and are best planted in troughs (stone cattle troughs are perfect). There are plenty of rock garden plants which tend to be a little larger, such as creeping thyme, phlox subulata, phlox douglasii, dianthus, gentian, and many others which give a better covering to a largescale rockery. Include a few larger plants such as tiny alpine willows, miniature juniper etc, but do check their final size.
Alpine strawbs are not really well suited to a rockery for two reasons - one is that they prefer a damp slightly shaded position, the other is that they seed themselves around if they do like where they are, so although they are tiny they will take over. I find them delicious.
I might manage to post some pics of my rockery and alpine troughs to give you some ideas. Mine is made from local stratified rocks, so easier to make them look natural than big boulders possibly.