3. Unless you plan to hold the line in your teeth when you get to the mast head
, you need a cleat on the lower block, so that means a built-in cam cleat in the block..
This is a really important point but I personally would never trust a cam cleat with my life, they slip, the line could be wet or slimy, the teeth worn etc.
I would tie off the line to whatever the bottom block was tied off to, probably the harness.
The other issue is that folks who do this take other precautions:
1. They know the rig and the condition of all the parts including spreaders. If something goes wrong and you can't go up or down it can be a puzzle as to what to do. Don't ask how I know this. If the rig has not been inspected in years you don't go up it period.
2. You never use the shackle on the halyard. Use a bowline.
3. Make sure someone else is around.
4. Bring a light line with you so someone on the ground can tie off the tool you forgot.
5. Bring a short length of line or special strap to tie yourself of to the mast when appropriate.
6. You may need to rig some kind of foot stirrup if you need to get to the very top of the mast as the blocks and halyard and sitting posture may not get you high enough.
7. And of course you test all this stuff out three feet off the deck before you go all the way up.
If you are going to just have someone winch you up you need two helpers. One to winch and one to tail
even if you have a self tailing winch.