It's a lot of fun to pick out fabrics for these - and a bit of a challenge to find plenty of boyish prints. I use flannel for these because it's soft and absorbent. I have never understood the vinyl bib concept - food and drink slide off the bib and onto the clothes.
Velcro is a good option. I know this because I've put on and taken off thousands of bibs on small necks and ties are no good. Snaps work all right, though, and are quicker to install.
A quick how-to:
1. Make a bib template on clear plastic or stiff paper.
2. Trace two bib pieces onto flannel.
3. Stitch right sides together leaving a small opening (2-3 inches) at the bottom of the bib.
4. Turn right side out, using a long, pointed object to help.
5. Press bib, taking care to press the seam allowance in the small opening under so that it is even with the rest of the bottom edge.
6. Topstitch around the edges.
7. Add velcro or snaps.