One thing I did which REALLY helped me get punchy, crisp prose was micro-fiction. Keeping stories to 1K words or less. I used to participate in #FridayFlash, which was limited to about a thousand words for an entry.
I also saw an amazing number of entries, which further inspired me.
During that time, someone suggested reading and writing poetry. Some poets have a wonderful knack for turning tight, descriptive phrases, and wow, was it eye-opening! So, give your hand a try at writing poetry, and read as much of it as you can too.
Finally, imitation is a brilliant teacher. If you have a particular author you like, who has a style you really like and would like to match, you can take one of their passages, which had impact on you for whatever reason, and re-type it. Just...type what's on the page. Copy it, word for word. (This is, of course, for your OWN benefit, and not for show, on the web or elsewhere.)
Doing that sometimes unlocks something in the creative mind. You see what they did, why, how, and you can incorporate that technique into your own work. I personally haven't tried this, but I know at least one or two pro authors teach this as a way of learning the craft of storytelling.
I hope that helps a bit, and keep at it! :)