Addict:
I gave up buying built rods about 15 years ago and have built all of mine since. I am no pro by any means but have built enough to offer some humble advice. This advice is definitely not the gospel but is based on mistakes I made learning the hard way. Take it for what it is worth!
1) Don't tape the butt of your blank to take up the slack for a handle with too big a hole. Some manufacturers have been guilty of this and over time the tape will fail and you will have a loose handle. When buying the cork for your handle, get one with a hole too small then auger it out until you have a tight (but not super tight) fit. This will ensure the epoxy adheres evenly up and down the blank and handle.
2)File down the ends of the feet of your guides; kind of like a wedge shape. When wrapping the thread and you get to the end of the feet of the guide it will make for a smooth transition when going from the feet to the blank. Some guides come this way, some need filing.
3) Use color coat on your wrappings before varnishing. Some guys skip this step but it will lock the threads in place as well as preserve the color-only takes a short time; might as well do it.
4)Line up your guides on the blank before wrapping. It can be tricky and usually takes 2-3 tries to get them just right-depends how picky you are. Just remember anything less than perfect will mean line resistance when you cast-resulting in a shorter cast with more effort. Some guys tape 1 foot to the blank, others use rubber cement. I use tape because it is more forgiving when making adjustments.
5) I recommend using "flex-coat" for the finish on your wrappings. It is a one application coating, lasts well, and is easy to use. Just don't let it sit once mixed. Apply it right away.
6) find some way to turn your blank as the coating is drying. This will eliminate drooping on one side. If you don't have a machine, turn it 180 degrees every 10-15 minutes for about 3 hours. This is what I do because I don't have a machine either and it works fine for me.
Whew! That's all.
Good luck