Dreads do get fatter with time, because the hair that would have fallen out, builds up inside the dread. This is what makes the dreads become hard after a while. But if you want really big dreads and you haven't started them yet it's easy to make them fat, just make bigger sections. And it's pretty easy to make the bigger if the dreads are only about two months old or younger, just rubber band them together and palm roll them as much as you can. But once they are hard it's really hard to connect them, you can still rubber band them together, but you take a chance of having folds or creases in your dreads.

The best way to have thin dreads is to make the sections thin when you start them. There really isn't a good way to thin them once you have already put them in. You can tie string around the roots and make them grow in thinner sections, but if cut them or pull them apart it really tears up the dread.

If you cover them with a nylon when you sleep it will make them lay down.

There are two kinds of flat dreads
1. Dreads that were made using rectangular sections, there's really nothing you can do to make these dreads round, because they start out flat. If you want round dreads section the dread into two sections at the roots using a string, and they will start growing round.
2. Helmet/hat/sleep head dreads- these can be poofed back up by palm rolling or washing.

It's not really a good idea, because the dread will start to unravel because the hair that was holding the knots together before is gone. You will have to wait for the tip to lock up again and it's just a pain. But if you are going to do it the best way to cut it is like a flower, cut it at an angle.

There are a couple ways of doing this
1. Roll the hairs into and ball and try to stick it in the dread, the put a rubber band around that area, wax it, and palm roll it
2. Try to thread it through the dread using a dental flosser