I’ve made a couple of dowel jigs to use on a table and bench project that I’m making from 2×12 Southern Yellow Pine. One is useful for joining two pieces of 2 by # lumber and the other is for 4×4 lumber. They’re very inexpensive as they are made from a scrap piece of 1” oak and some “steel spacers” from Lowes. Both have proven to be accurate and easy to use.
-- Visit my Youtube Channel: https://www.youtube.com/playlist?list=PLFZY9FU6f7lo2tUgJOnqCzBV3qxJzAVDA