The most important thing to learn, at least it has been for me, is that oil and lemon (or lime) is really all you need, especially in the spring and summer when fresh veggies are so full of natural flavor and goodness. I find that oil and red wine vinegar is what I use more of in the fall and winter, but red wine vinegar, (and, God forbid, lol) balsamic vinegar, pairs with tomatoes prefectly.
Once you start making your own dressings you won't use store bought again (another blog post!) Dressing are simply 2 things....oil (fat), and acid like vinegar or citrus, etc.. (I promise this will be a seperate blog post soon!)
I've been using brown rice and quinoa in alot of my salads to make them a little more substantial, adding in chicken as my protein.....chicken is not my first choice, but because I've been making so much stinkin' chicken stock lately, I have so much of it pre-cooked, anyway.....if you start with:
a grain, or carb, brown rice, quinoa, barley, pasta, bean, legume, etc.
a protein, chicken, shrimp, pork, beef (leftovers are great for 'next day salads), hard boiled egg, etc.
lettuce greens, spinach, arugula, baby greens, romaine, butter, chard, etc..
Any leftover veggies, especially grilled or roasted (again, you should always, always cook more for this reason), summer squash, asparagus, eggplant, corn (not really a veggie but..), red bell, cauliflower, brussels, onions etc.
raw veggies, tomato, (of course), green/red onion, shredded carrot, jalapeno, red bell, red cabbage, mushrooms, broccoli, sprouts, celery, anything super fresh and special from the farmers markets, etc.
a fruit!, either dried or fresh...no excuse for not using fresh especially in the summer! Grapes (raisins), peach, plum (prune), apricot, orange, mango, strawberry, apple, fig, etc.
other stuff like, olives, capers, anchovy, nuts and cheese (in moderation), etc.
Dress salad with oil and lemon and life is good!