"So I totally saw this on Pinterest and had to make them." Yes, it's become my catch phrase. But I totally did see them on Pinterest and I totally did have to make them. So easy and really this doesn't need much of a tutorial. You will need to gather these supplies...yarn, tacky glue or any glue, really, that dries clear, mod podge, fine, you get it...empty, clean jars, cans, whathaveyou. Paintbrush and something to put the glue into. Scissors. Put something down to work on so you don't get glue on EVERYTHING YOU OWN! Or you could have fugly formica like me and not give a crap.
Start painting the glue onto the jar or can. If you are using a jar or bottle with a lid, and want to use the lid (maybe you are going to use this yarn-covered jar for storing herbs or buttons or whatever), do not put yarn on the threaded neck of the jar. And you will want to paint the lid to compliment the color of your yarn.
I didn't even take the labels off. Deal with that. I knew I wanted to use these for vases so I put glue on the threaded part. Now start wrapping your yarn around the jar. Keep your beginning yarn end down and start wrapping it under the yarn wrap. I did this in sections so my hands didn't get all glue-y, except they still do. Wrap the yarn so you can't see any of the jar.
Keep doing this until you get to the bottom and add a little glue to the end of your yarn. Then you will become obsessed with doing this and make many, many yarn-wrapped jars. I put flowers in it, then I put a candle in the other, then I put them downstairs and then upstairs. And now I am making more.