I just jumped into the portal, no planning, just did it. I ran out of arrows, silly me! I didn't even have enough blocks to pillar up after shooting off all my arrows, to then but the last crystal.
oh and silly me ran off and LEFT THE DRAGON EGG, HAHAHA! anyway, now I can get onto some shulker boxes and some elytra wings and then my ROOF BLOCKS :P
now I have End Stone :)