Hi Penguins, I know this can be a real pain in the ass,er belly. This took me a long time and got a lot of help from our great ostimates. So to business: first, I believe you mentioned you had a measuring card with all the different sizes, well that was my starting point, so you have an ovate shaped stoma, if you try a few of the holes and find one that will slip over your stoma, of course you'll have a bare spot but you know the size of hole you're going to need, next you get some adapt rings, or seals, whatever, eaking as long as you have a seal, next you warm it up a bit with a hairdryer on low for about 20 secs turning it over occasionally. Here it would be really useful if I knew the approximate size of your stoma, so we'll say at its longest point its one inch, so if you slip it over your thumb and stretch as you get to your knuckle. Now there are two tabs on the seal covers and you use them as a guide to where you are going to stretch it to your longest area and try and see where you need more or less, it will take a few tries but you'll be able to see where it fits or not, ideally if you can arrive at a size that might have just a slight squeeze, say about 1/32". Now if you can get that seal as close as possible to your stoma and it looks like a good fit, next you remove the paper tab on what will be the back so when you put it on you'll still have the paper covering on the front, which makes it easier to run you finger around the seal and when you feel you have a good connection, just peel away the front paper. Now when you place the flange on top of the seal you wont have to worry about anything getting by the seal as now you have the seal and the flange all stuck together. And now you can think about getting your flanges pre cut to the largest size that fits over your stoma and now you just slap on your pouch and away you poo, er, go. I hope you can make some sense out of this as its the first time I've tried to explain my method while typing. And if you have any questions I could help with just give me a shout, take care and good luck, Ed