Don't blow through your stash on that Golbat. Recover your Poké Balls!
UPDATE: It turns out this doesn't work anymore! Our suspicion is this was a bug that has since been resolved in the game, but it's clear this trick no longer works.
In the first few hours of playing Pokémon Go, you're going to waste a lot of Poké Balls. Learning to get that flick just right, watching as the ball bounced off of your critter while it tries to attack you, or missing in an attempt to rock a perfect curveball are high on the list. The failed attempt slowly rolls off screen, leaving you ready to grab another Poké Ball and give it another good toss. Actually, it turns out you can recover most of those lost Poké Balls, as long as you're fast enough!
This couldn't be more simple. Tap the Poké Ball before it rolls off the screen after a failed throw, and that Poké Ball will be returned to your inventory. It doesn't work every single time, but it works most of the time and it makes a huge difference when forced to rely on a limited inventory to catch a Pokémon that is being particularly difficult.
Don't let those Poké Balls go to waste. Get out there and have some fun!