propane torch and Bohning Ferr-L-Tite
You can use a butane cigarette lighter; or a candle; but you really have to be careful not to allow any soot to remain on any surface- it interferes with the bond.
Most broadheads and target/field/steel blunts - need any oil etc that might be inside the point where the glue will go. Heat it first; and then heat up the glue; and scrape some off into the broadhead or point; then heat the tip a little more and push and twist onto the tapered wood arrow end. If you use an aluminum insert- heat it too: before pushing on the point.
With broadheads; point the head down on a hard surface and spin the arrow. If the shaft at the point the broadhead sits wobbles; then you need to straighten it up.
What I do; is to take a piece of wood and with a cooled arrow with a broadhead on it. Push the point in just a bit; and twist the shaft until it spins.
Now - heat up the wobbly headed point; and put it point down into that hole; and turn it slowly. By looking at a still object in the background; and slowly turning the arrow; you can see when the shaft is off; and by pushing the arrow to straighten it- you can straighten it perfectly. You probably will have to heat up the point a few times to get it right; but this method has worked for me for 3 decades.
I like my broadheads ( 2 blades ) to line up with the nock so that the blade is horizonal when the bow is held perfectly straight up and down. When setting the broadheads and spin testing them; I will set the broadhead at that time to the right position.
A candle or a small flame may not heat the ferr-L-Tite enough to get the best bond; a propane torch seems to be the best way to do it ( or the torch shown above).