I disagree with the lifting the tip thing, it is too tiring due to treading water hard and lifting for some time. Learn to waterstart with that technique and in light to moderate winds and you'lll be stuffed in 2mins. Also you only nee dot move a little bit laterally and the wind will come from the leech side and work against you.
Far better (IMHO) is:
-do it when almost overpowered (so at the point of being lifted out of the water you have little choice in it lol)
-mast across wind, nose of board into the wind
-lift boom head a little and frog kick backwards HARD into the wind.... once or twice will do it and the rig will be flying 30cm above the water all by itself. That has taken 2sec, not 20sec of kicking hard and working ur way down the mast only to have some chop break over the mast tip when u r halfway (and push u underwater again).
Then hold boom and use the power in the sail to push the nose of the board downwind.... the sail is supporting ur weight and driving the nose downwind into the broad reach position that you want. (Beach starting will assist with this rig steering technique)
Thereafter, it is the same.
Tip - not having a 100cm wide board helps too, width can make it harder to get your leg over.