By cutlets I'll assume you mean breasts that are already chopped and trimmed up. There's already no prepwork there, so you're in luck.
You'll want to dry the cutlets with a paper towel, the slime around them will just prevent searing, so it needs to be sopped up.
Put the cutlets in a bowl.
You need kosher salt. It's way too easy to oversalt with table salt, so just start buying kosher salt from now on, ok? Take a small handful of k.salt and drop it in.
Next, people usually go to pepper, I'm a little different. My go to spice is hungarian paprika. It's the sweeter kind, not hot like cayenne pepper. Not only will it give you a nice flavor, but it will give the chicken a really great color. 1-3 tablespoons depending on how much chicken you have.
That's usually my base spices, you don't have to do anything else. If you want to here are some very easy options:
Sage - sage loves chicken. If you can get sage fresh that's probably where you want to go. Ribbon it and throw it in the bowl. What's nice about fresh herbs is you can't go wrong with too much. The same applies to basil, cilantro, parsley, pretty much anything leafy, it'll all taste great as long as it's fresh.
Lime or lemon. Do you know how to zest a lime? You'll need a micro grater, it's absolutely worth it and really adds a kick to flavor. You can also juice the lime into the bowl.
Fresh peppers - you can use any peppers you want, any heat level, even mix and match, as long as they're fresh (notice a theme here?). 1 Serrano pepper chopped finely will give you some nice flavor and a bit of kick. You can keep the seeds, if they're too hot for you use a more mild pepper.
If you're going to use any dried spices use them sparingly, they can easily overcome the flavor. They are especially dangerous with chicken because there is no way to taste it before it's cooked (unless you want to poison yourself).
Oil. 1-2 tablespoons of oil coating everything will promote searing. If you want to grill the chicken it'll insure those nice grill lines before the chicken dries out.
If you are cooking it up in a pan/walk/etc, cook some onions first in a pad of butter. Let them brown up the bottom of the pan, then drop in some lime juice. Onions love lime juice. Move then to the side them cook the chicken.
Simple and easy. Remember, chicken has no flavor, it's extremely bland. Salt is a start, but if you don't bring your own party to the table don't expect much in return. I like to use fresh ingredients, and I like to use smaller pieces of chicken (like cutlets). I have never had a chicken breast that wouldn't have been better had it been cutletted up first (well, maybe if it was brined, but that's a different thread).