Cleat Hitching -- Forms, style, etiquette?!

[Brion Toss]

Hello,
I've been so long in getting back to this because it is a big can of variables, fit for more of an essay than I can do here. But the short form is that the rule of thumb I learned, long ago, is that a cleat should have an inch of length for every sixteenth of an inch of line diameter. So a 1/4" line takes a 4" cleat, and a 3/4" line takes a 12" cleat. The idea is that this will give you a cleat that is strong enough for the line, big enough that the turns don't get kinked or crowded, and has enough bearing surface to generate enough friction that two full turns will make for a good belay (i.e., no slippage, no jamming of the finishing hitch, control of load at the first turn).
The problem is that this rule of thumb was developed in the days of natural fibers, which are at best half the strength of synthetics, and usually less slick. A further problem is that manufacturers seem to delight in undersizing cleats -- how many times have you had to deal with trying to jam a line onto a dinky little cleat?
So first, make sure that you have the right size cleat, and that it is installed and backed correctly. Then you might want to add an extra half turn before the finish, to generate a bit more friction. If you need to belay a too-small line to the cleat, err on the "knitting" side of things, to get more rope surface area on the cleat, to prevent slipping and jamming.
As for rings and other non-cleat items, like rails and posts, some version of the Capstan Hitch, usually made with a bight, is my first choice. Another option is a Round Turn, again with the bight, if the line is long, followed by a Camel Hitch or Camel Rigger's Hitch. A third, and very attractive alternative, where practicable, is to take the line through the ring and back to the boat. You get a doubled line, and a belay you can control from on board.
Fair leads,
Brion Toss