Pulling up slack rope? Try a redirect
This video comes from IFMGA Certified Guide Karsten Delap. Connect with Karsten and see more tips like this on his Instagram, YouTube, and website.
When you finish a pitch, you need to pull up the slack before you put your second on belay. Yes, this is a pretty simple process and usually you don’t need to overthink it, just start pulling the rope up hand over hand.
However depending on your stance, anchor configuration, rope friction on the terrain below, and the amount of rope you need to pull up, simply redirecting the rope through a carabiner clipped to the anchor can increase your speed, efficiency, and comfort. If you're making lap coils, or even a pancake stack on a nice ledge, redirecting through a high point usually keeps things more tidy.
This method also has the benefit of working out most of the kinks or twists in the rope while you're doing it.
The same trick works really well if you need to stack a rope inside a rope bag or a backpack. If you don't have a high anchor point, like on the top of a climb, put the pack or rope bag on the ground in front of you, drape the rope over one shoulder, and pull the rope down hand over hand into the pack.
Here's a nice diagram from @climbing.technical showing the “over the back” method. (If you just have a T shirt, watch out for rope burn. =^)
Like many things in climbing, it's a better show than a tell.
Here's a short video by IFMGA Guide Karsten Delap showing the technique.