If you're looking to perfect your bar technique, you need to learn how to perform common bar tasks, such as muddling mint without ripping the leaves and the "dry shake," which makes cocktails with egg white in them foam up. The folks at Serious Eats have all this and more covered in their cocktail mixing guide.
Serious Eats' massive guide to making great cocktails at home is a worthwhile read. It walks you through the kind of equipment and barware you actually need at home to make great mixed drinks, and then covers techniques to produce exotic drinks. An example, from the muddling section:
Take a close look at a mint leaf: you should see little veins running through it like little rivers and streams. Those veins contain chlorophyll, and as it turns out, chlorophyll is bitter. So the worst mistake you can make while muddling is to crush or shred mint leaves so they release their bitter chlorophyll. Where will that chlorophyll wind up? In your cocktail. Yuck. If you've ever had a grassy-tasting mojito, that's probably why.
You can use a variety of items to muddle a drink; there's no actual need to go out and buy a muddler. The handle of a rolling pin will do in a pinch. If you do buy a muddler, be careful what you buy. You want a muddler that has not been varnished or lacquered. The varnish on a muddler will eventually wear off, and where will it wind up?
In your cocktail. Yuck.
So choose a muddler made of unvarnished wood. You may also see muddlers made of stainless steel with a plastic or hard-rubber muddling base, and those are fine too. (But avoid the type with teeth on the end; they're great for muddling the juice and oils from fruit, but they will shred the leaves of mint and other herbs.)
It's a huge guide, so bookmark it and work your way through it, or use the TOC at the top to skip around to the parts that interest you the most. With this in your pocket, you'll be making pisco sours, old-fashioneds, mojitos and gin fizzes at home in no time.