Baseball players use spring training to fine-tune their fundamentals. It doesn't matter which nuance of the game they're working on, spring training presents a time to get back to basics. I've taken spring as a good time to brush up on the ABCs of wine tasting.
I find it useful, for example, to taste more than one kind of wine at a time. It allows for comparative analysis purposes.
It can be any kind of wine provided there are two, or even more if you like. What I've learned is that there are ways to see similarities in certain wines, such as Petite Sirah and Zinfandel, or ones that are seemingly opposites, such as a late-harvest Sémillon vs. Chardonnay, or even a Syrah vs. a Riesling.
What you learn from comparing different types and styles of wine highlights varietal character, wine weight and viscosity, aromas, oak influence, earthiness and herbs or spices, etc. One place you can start is right here online at WineSpectator.com's Learn Wine section.
I often meet people who want wine-buying advice, and I routinely direct them to our Daily Wine Picks page—the range of wine values is impressive, even for those of us who taste on a daily basis.
Yesterday's under-$15 pick was my recommendation of Bridlewood California Pinot Noir 2015 (88 points). At $13, I don't see how you can lose by trying it. You'll almost certainly learn something about the wine and, ultimately, your preferences.