Dealing with Ends
Weaving in ends is one of those things where there isn’t really a universal “right” way to do it but rather all kinds of techniques depending on project and preference.
I’ll admit to not being the best reference for weaving in ends. I leave them all until the end, and then I sort of…fake it. My best tips are to leave a long enough tail and to aim for a place where there’s a more solid stitch, like garter or stockinette, and avoid lace if you can. If the surrounding fabric is solid enough to handle the extra bulk (garter stitch is usually a good candidate), the colors aren’t too different from one another, and your FO doesn’t need to be perfect, you can weave two adjacent ends in together, threaded through the same needle.
Other Weaving-In Techniques
Though I don’t agree with everything in this post by Kate Atherley on Modern Daily Knitting (I typically weave ends in before blocking, for instance, at least on accessories), it covers a lot of different options and types of fabric: seam allowances, stockinette, garter, ribbing, lace, and two-sided fabric.
Stephen West uses a technique he calls Weavin’ Stephen, demonstrated here (the same video is also on Instagram):
There are also plenty of videos about weaving in ends on YouTube. If you find a particularly good one, do let me know!
Carrying Colors Up the Side
When working with more than one color, you will sometimes need to either cut the yarn frequently and weave in a lot of ends or carry an unused yarn up the side of your work until it is used again. If you prefer the latter, the following video may be helpful. Personally, I like this technique if I’m carrying the color a short distance, but I typically prefer to cut the yarn for anything more than four rows.