I like your color choice, it's primarily up to the stitcher as to what colors work well with others, so I'm sure you'll be figuring that out as you go.
Tips-
1- It does look like you've use a bit much on gather. After the stitches have evened out around the pentagon there should be room for filler to come in and out of the pentagon, but not too much or it will take on an overly floppy feel. Experiment, it's all about finding what works for your stitching style.
2- Try concentrating on keeping your stitches in a straight line across the panel.
3- How many holes are you putting in your pentagons? it looks like 4 to me. With a 2-stitch bag (4 holes) you may have to stitch a bit further from the edge than if you were to put a 3rd stitch in there. If your stitches aren't perfectly lined up you'll be able to see a little gap between the panels where it will turn out when filled. The bag will still play fine, i made one about a year ago where every single stitch turned out, but it's one of the best bags i own...
4- Filler: Aquarium rocks are okay for when you first start, but ideally you want something small and round. Shot is ideal, preferably lead, and not BBs. I use #9 nickle plated lead shot. this is where I get it from
https://shop2.mailordercentral.com/bpic ... umber=NP09
This is a pretty large quantity, enough to make around 100 bags.
Consistency Consistency Consistency
Not too bad for your first bags, to make one come out nice and round it's all about consistency. These are just geometric shapes, so if we can get them all the same, we'll have a nice round ball.
I hope some of this helps. It looks like you've already read a tutorial or something, so you have a pretty go idea of how the bag is structured. Most stitchers claim their best bags started coming out around #40, but you can pump out something quite playable in your first 10-20 without much trouble. You're off to a better start than I was
