i basicaly cut out the cups of an old bra pined two pieces of material faces together inbetween the two cups! im sorry if this isnt making much sense. i then sew a square open at one end big enough for my camera. i didnt measure anything so i was lucky that it fit my camera perfectly but i wouldnt recomend doing this unless you have a good spacial awareness.
i dont have a sewing machine so this did take me a while as it can be very hard sewing through this thickness of material.
i messed up the top on one side. oh well you can learn from my mistakes lol!
if you have any questions just ask ill try my best to answer.