From NerferWiki

There are various aspect of creating homemade darts (stefans), that when followed carefully, can produce a fantastic batch, which can put any stock dart to shame.

Selecting your Foam

Some go to their local hardware store to purchase FBR (Foam Backer Rod), while others purchase online.

The Process

The typical process of creating a Stefan dart involves:

• Straightening, through heat or stretching

The most popular method of straightening dart blanks is to put them in an old pillowcase, rubberband or clip the end closed, and throw the pillowcase in a dryer for about half an hour, or until the blanks are straight.

• Cutting, but be careful, because any miscut can alter the balance of your dart

It generally helps to use a straight razor to cut the foam, as it doesn't pinch the ends as much, and is much easier to control.

• Drilling or Burning a hole in the tip for the weight to rest in

The tip of a hot glue gun is easiest for this, as you can also squirt a small dot of hot glue in, to hold the weight in place.

• Weighting, which is putting a suitable weight onto the head of your darts

The most common weights are steel BBs, 3/0 fishing weights, and 1/4" steel slingshot ammunition. However, weights can be anything, from wire to washers.

• Doming, which is making a dome of hot glue on the dart tip to cover the weight and make the dart more aerodynamic.

When doming, it helps to lick the tip of your finger when smoothing out ripples in the dome.

After your dart is cooled, test it in an appropriate blaster to insure quality control.

Then, do it again. But feel free to do more than one dart at a time.

To Add:

Fitting Stefans to your barrel.

Often you end up with foam that just isn't right for your barrels. Well, there is one specific technique that can make quite a difference. This technique is known as foam stretching. It slightly reduces the diameter of foam that is just too large for your barrel material. Note that it is more effective when stretched before and after heating.