Tucking carpet edges neatly isn't hard-it just takes a little patience, and the right trick. Kinda like folding a fitted sheet, y'know? Once you figure it out, it's easy, but before that? Total chaos. I've messed up so many edges-lumpy ones, ones that popped right back up, even one that looked like a 皱巴巴的 sock. So I'm gonna tell you exactly what works, no fluff.
First, prep the area. Make sure the carpet is pulled tight! If it's loose, tucking it will just make it bunch up later. Use your free hand to pull the carpet toward the wall-like you're stretching a yoga mat to get rid of all the wrinkles. Once it's tight, grab your tucking knife (don't use a cheap one-those are more trouble than they're worth) and hold it at a shallow angle, like 30 or 45 degrees. You want the blade against the back of the carpet, not the front-you don't wanna ruin the fibers!
Then just slide the knife along the edge, pushing the carpet into that little gap between the baseboard and the tack strip (that's the strip with the tiny nails that holds the carpet down). It's like tucking a napkin into a plate-slow and steady, no sudden moves. Corners are tricky, so take your time. Don't just jam the knife in! Make a little notch in the carpet's backing (just the backing, not the fibers) so it bends easy. Then twist the knife a little to follow the corner, tucking a little at a time.
After you're done, run a rolling pin or a carpet roller over the edge-press it down good. That helps it stay in place and gets rid of any tiny bumps. Oh, and if the edge keeps popping up? Check the tack strip-if the nails are loose, hammer 'em down a little (gently, though! You don't wanna damage the floor). Do all that, and your carpet edges will look so neat, people will ask if you hired a pro. I've had neighbors say that, and I just laugh and tell 'em it's all about the right tool and not rushing.
