If you still have the router bit for the dovetail, keep it around. I use mine to lay out the pins first. Others may do tails, I find pins first is way easier to cut, chop, and then lay out the tails using those pins.
Make a stop/base line all the way around. It should match the thickness of the other half of the joint.....3/4" to 3/4"
Use that old bit, mark out the "half" pins on each end. Then flip the bit a bit, and work towards the center of the board...
I also use a sliding bevel gauge to do most of the lines. ( Usual suspects..)
Usual rip saw/backsaw. As long as it is filed rip. Small square to mark the cut lines done to the base line. I use those the see where to saw at. I try to split these lines.....doesn't matter on pins. Once you use the pins to mark the tails out, the tails will match.
I clamp the sawn board down to the bench. I chop down only half way through. Don't get in a hurry, as they will just blow out the other side if you try to do it in one shot. Flip the board over, and clean things up...
Should look like this. The skinny/ pointy part of the pins goes to the outside of the joint. Remember that point. Stand this board straight up, and even with the end of the tail board. Use a sharp pencil/knife/whatever to mark the waste side of the tails. When you cut the waste away. LEAVE the lines.
I have a hard time sawing angled cuts, but, if I lay the tail board on my bandsaw's table, I can see where to cut a lot better. And straighter. I then chop out the waste, again from both faces of the board.
Once you get here, you can do a test fit. Sharp chisel to pare away any spots that are too tight.
Hopefully they will look like these.
Paul Sellers has a few videos out there, about how he does his.