Keep the tip clean between heat applications -- a wet cellulose free sponge (the yellow one's that look like Sponge Bob). Quick wipe between heat applications will remove the oxidation that builds up keeping the tip shinny. Also remember to lay the sodler cross the item being soldered and bring the tip down on 1/16 - 1/8 of an inch of the solder then remove the solder. This will place a small amount on the tip in contact with the item for much better heat transfer. Feed from the far end of the joint (should run to heat). Another thing not posted here yet, the items that you are soldering, must be completely stable. A joint must not move during cooling (never quench). Keep the tip tinned. Also, butane driven soldering irons also work great.