Not quite hot enough for you to wear just a T-shirt and shorts, but not so cold that you need to bust out the wool peacoat. You need something that can protect you from a cool breeze, but not have you sweating in direct sunlight.
Well, I never thought I'd be saying this, but I've found that the perfect medium piece for springtime is... the denim jacket.
To be honest, I've never really had a liking for denim jackets up till the very recent past. Generally all denim jackets I had seen prior to last year were fitted awkwardly, wildly distressed, and of course, paired incorrectly (think light wash denim on light wash denim). The types of people wearing them were also usually in their fifties, and looking like they were going through some sort of midlife crisis.
Well, the good news is that things have changed, as they often do in the fashion world. The denim jacket is back and looking great, especially when incorporated into the appropriate outfit.
There are a couple things that you should know when looking for the right denim jacket:
1. A denim jacket should feel snug. It can even be used for layering, so you want to minimize bulk as much as possible.
2. The color of your denim jacket should not match most of your denim pants. If you do somehow end up pairing denims, you want to at least make sure they aren't of similar color. Just FYI, I would recommend chinos or cords to be safe.
3. Make sure the shoulders fit perfectly on the jacket, as that measurement will be the most important in determining whether the jacket fits you or not. Alterations can be made elsewhere, but not on the shoulders.
4. I don't think you necessarily need to spend a lot of money to get a good denim jacket. I've found that the Gap one I bought for $50 is rock solid in construction, and feels like it won't be falling apart anytime soon. My Levi's one from ten years ago is also going on strong, with no indication of slowing down.
5. Start with a less-distressed jacket, and give the jacket some of your own character. Like denim jeans, you'll start noticing whiskering, distressing, and other marks on your jacket as you wear them in. You'll probably find that you enjoy distress marks more when you're actually the one contributing.
Here are a couple denim jackets at different price points that I would recommend:
~$50 : Gap
~$125+: BLK DNM
Keep it simple, find one that fits well, and you'll be getting compliments in no time. Give it a try, it might be worth the effort and money! Good luck fellas.