I can't cut straight with my bandsaw!!!

[Mugz]

I use a hand coping saw for all my lips. $10 at Homies. I tried using my band saw with the smallest/thinnest blade I can buy and still makes the lip slots too big. I like the tight fit the coping saw gives.
I use a piece of tape as a guide to follow......easy to get the hang of.
Takes 1 minute longer than the band saw, but is worth it. I screw less of them up and it is more forgiving. One slip on the band saw and your plug is scrap.
I have some rubber in my vise so I don't mar the wood (usually still needs a quick sanding afterwards) and saw the lip. Cuts like butter and is easier to stay on line.
Good alternative for you and cheap.