Gluing your pointe shoes is essential to their longevity. I wear Freed, and I absolutely do not take one step in my pointe shoes without gluing them inside and out. Everyone has their own preference with this. Some like to shape their shoes a little before they glue. I however like a strong box and for the platform to remain flat and square so that I feel straight on my box and lifted in my shoes. I also glue the interior and exterior edges of the shank.
In terms of which brand of glue I use, I choose Hot Stuff. I was introduced to Hot Stuff when I danced in the Professional Division at Pacific Northwest Ballet several years back. It is what the company uses for pointe shoe glue. I know Jet Glue is very popular (and works well) but Hot Stuff is exactly the same and is actually cheaper! I also prefer Hot Stuff for it's applicator which has a lid that protects better from spills than Jet Glue. DISCLAIMER: Do not put the lid back on the applicator with wet glue on it. I wipe the excess glue off of the applicator with a paper towel or let it dry before putting the lid back on. You don't want to glue it shut! It is also crucial to keep your glue bottle upright in a tupperware or ziplock. I can't even count how many dance bags I have ruined because it toppled over. This stuff is no joke. One drop can do a lot of damage!