I regularly make my own dressing as well! I have a few basic recipes—most are pretty much the same as yours. One I like in the summer especially is a really simple one:
+ 2 parts olive oil
+ 1 part honey (try and make it good wildflower or clover honey)
+ 1 part squeezed lemon juice (add some zest as well if you're feeling energetic—I hate cleaning graters)
+ Salt & pepper to taste