These are my newest crocheted jar covers. I have tons of jars in various sizes that store my beads, buttons, left over yarn and some of them have fabric covers while others are coverless.
This is a pattern you can use for any size of lid.
Start by chaining 5. Join to make ring. Next sc2 in each st for 4-5 rounds. In the next rounds, sc 1 around until you get the desired width.
For example for this particular lid I stopped increasing at 40 st in round, then sc around for several rounds until I could slip the lid inside.
By following this pattern, the crochet work will start rounding, getting an elliptical shape (see picture below).
When the lid was completely covered I crocheted 2sctog, made 1 picot, skipped 1 and repeated this pattern around.
That's it. When finished I inserted a contrasting thread to make the edging more prominent.