what I use is a wooden stick and then use old bycicle inner tube on the ends to put on the extra weight.
this my current one (not contact just a jack of all trades) I changed it a bit by adding another inner tube so the ends are a bit wider and its pure black/white now

I'll tell you how I've made it. I just went to a local bike repair shop asked if they had any inner tubes they wanted to get rid of and if i could have some
You need to get 2 that are the same and one extra that doesn't realy matter much.
then go to your local hardware store and buy a piece of wooden dowel (aka round piece of wood) of your prefered size.
and buy some grippy tape at yer sports store.
you'll also need some ductape and colored isolation tape to decorate it
you start by cutting of the vents on the inner tubes and cutting them open (either with a knife of scissors, I recomend the scissors) do that with all your tubes.
now mark the exact center of your staff with a bit of tape.
then put a bit of ductape on the end and tape it on the end of your stick then just wrap it around the stick as tightly as possible and secure it with ductape.
do this with both sides. if you are happy about the weight then you can start decorating if not cut the 3rd innertube in half and wrap in around the stick next to the other ones.
still not happy add more or remove a bit
remember the bit of tape you put in the center? now you can wrap the grippy tape around that but make sure you remember where the center is and then put another bit of tape on it so you know where the center is.
try to balance your stick by adding extra ductape to the ends till is nice and balanced
and then you can start decorating just remember to keep it balanced.
anyways I hope I didn't confuse you too much and good luck!