Quilting borders or not
 

If you did a SITD around the perimeter (the ditch between the border and the main part of the quilt), do you need to quilt in the borders? Or can you leave it with no quilting? It's a 2" border

I think you could safely leave that unquilted.

I agree, if it's only a 2" border, you could leave it unquilted.

It depends on how densely the rest of your quilt is quilted & how often it will be washed. Borders, ideally, should be quilted at a density that is halfway between the closest & farthest apart quilting lines on the center of your quilt. If your quilt is quilted 2" or more apart & it's a wall hanging, you're fine with just doing SID around the perimeter. If it's an adult quilt, I'd probably add an extra short little line of stitching on each side from the middle of the perimeter out to the edge & maybe framing each corner (like a cornerstone), just to give it a bit of stability. If it's a quilt for an infant/toddler, I would definitely add a little quilting in the border so it doesn't get stretched out of shape.

I would ask what type of batting you used? some batting need to be quilted more than others. I usually like to quilt in the borders. Sometimes I just do loopy loop lines they are quick and I like how they look too.

Warm and natural batting. It's a twin quilt for my 7 year old. I want to quilt the borders but it seems to pucker when I try. Also, if I do straight lines, do I still need to start from the middle? And do I switch directions if there are two rows of straight lines?

with that narrow of border, how about using a wavey line down the middle of it--but don't use your walking foot--just the regular foot and you should be able to move it under the presser foot ok--check first with a practice sandwich and if it's not easy to move it in a wavey line, lessen the presser foot just a little.

I recommend using your walking foot - never just the regular presser foot - for this. You can make easy, gentle curves with the walking foot.

If it's only 2 inches, I'd leave it as is.