here's a way to make a jig pretty fast and cheap. don't worry, you don't need the tools i use. a simple handsaw can a drill can to the same.

Step 1: Get a Straight Beam and Saw It

get some good wood (i took pretty strong hardwood since it lasts longer.
saw it to lenght as straight as possible. i mitersaw or sawbox would help a lot!
the regular angle of a pocket hole is about 18 to 24degrees. so we drag a 22.5degrees line over the side of the wood so we can cut it later on. now we know the lengt we need to cut the wood to lenght.
next put some holes in it where you like them to be. 1,2 or 3 holes, all is possible. just make sure they are at the same line!
next drill the hole completely trough the wood. it is important that it is perfect in line with the wood to make it allinged afterwards. bad allignment=bad pocketholes!

Step 2: Sawing It at an Angle

i did mine with the mitersaw. it was a bit of a hassle since the way i want it to saw is not the normal thing on a miter. a mater can get a max degree of 45° and i needed a lot more.

SO

i turned the block 90° so i only needed a corner of 22.5°. to prevent it from moving a put some extra wood on the side and press it to the saw.

you can do this with a simple handsaw as well when you are pretty good at sawing straight with care (i did it ones and it worked too.) just make sure it is very very striaght and on the right angle.

Step 3: Glueing the Two Triangles Together

so now you have 2 triangles with holes in them.

put strong wood glue on the back and join them for the night like on the picture.

next day you can saw off the small sharp edges and sand them for esthetic look.

you can finish with some paint or varnish.

Step 4: First Test

putting a kreg drill into the drill(it my own made version of a normall HSS drill for metal.more later)

you see it looks pretty nice.

Step 5: Final Word

on these pics you see the drill where i had a tons of questions of.

it is not REAL kregjig drill. it is a normal HSS metal drill that has been manipulated.

how to manipulate?

i have put my drill into the drillpress and set it to full speed rotating in the air.

next i took my anglegrinder(yes, i'm crazy...) and made the diameter of the first 20mm of the drill smaller be holding the anglegrinderdisc spinning in opposit direction against is. slowly the diameter became smaller to the diameter i needed. next i resharpened all edges just like you would have sharpen any normal drill. it works like a charm, so me happy...

hope it works just as well for you as it has worked for me in the past.

don't forget the jig is a comsumable. if doing tons of pocketholes you will need to make some of them. they can wear out.