Several people talk about attaching the main halyard and use of a small "knot" so the sail goes all up the mast.
The simple and best way is to use a plastic "bauble" on the end of the halyard. Put it on and tie a small hitch to keep it on the halyard. then to attach just pass a loop of the rope through the eye at the top of the main and then pass the bauble through the loop. The sail is then safely attached without even having to tie any knot. The BONUS is that there is absolutely ZERO "knot space" and the sail goes all the way up to the eye.
We use the same technique for the spinnaker halyard, and also for the spinnaker tack where two baubles are best to produce about a 1 inch rope lenth so the tack is not right up against the pole. If you tie a knot it can get pulled inside the pole and jam.
We also use plastic baubles on the end of the main and jib halyards. They are one of the most useful extras you can get for your stratos!
I just tie a big stopper knot, a figure of 8 with about four 'rounds' instead of 1, and tie a single knot, the stopper knot cannot go through the single knot and so is very secure, get the halyard right up to the top... but plastic bobbles are equally as good.