There are a number of reasonable variations depending on exacally what you are trying to do.
For a fixed
mooring, where the
mooring has enough of a catenary that you don't need additional spring from the line, the best system I have seen was to use a triangle plate (similar to a split backstay plate), with the
single leg leading to the mooring. Then the double leg side was brought to the boat using two
dyneema lines, with thimbles at the plate end, and eye splices at the cleat.
This helps to minimize the primary failure point of nylon (at the chock where it comes on board) but requires something else to absorb shock loads (in this case either the mooring design, or the leader from the plate to the mooring should be nylon).
This won't
work for an anchor since it requires a fixed leingth everywhere.
Assuming you have an all chain rhode, then chain hooks
work great. Just splice a line from either side onto the hook then back to the cleat. Typically you see either three strand or double braided nylon here. I prefer the double braid, but Tom above seems to like three strand. This one is up to personal preference, do you want more stretch (three strand), or a higher breaking strength and abrasion resistance (double braid).