What I do is this.
I typically avoid changing a bag until flow has almost ceased by a prolong period of not eating or drinking. Usually overnight then in the morning after a nice shower with old bag removed. Hair.dryer (not hot) to dry up any skin moisture.
1: Fold and precut hole in sheet, can trim a bit to enlarge later.
2: Apply no-sting paste (brava) around stoma ever so slightly away from it and cutting the paste output in half using the nozzle as I apply it. It's difficult to work with and sticks to anything else easily so I smear it around in a circle around while pressing down and then pinching off while pressing down to remove it from my finger or nozzle. Difficult to explain anyway.
3: Next fold the sheet and test over stoma, trim to enlarge so it's a close fit around it, but not touching it.
4: Apply and press around to get the paste closer to the stoma but not oozing out, but if it does to pull the ooze back on top of the sheet. This method really allows a nice close fit around the stoma. If there gaps they can be filled in with the second layer of paste.
5: Apply the alcohol based, (it's more fluid) half level ring of paste close to stoma on top of sheet (fill any gaps near stoma) and apply appliance. Press down gently as not to get the hole blocked. Process also covers any gaps but alcohol based stings to let you know gap is covered.
Problem I was having was getting a good coverage of paste close to the stoma. Now with a visual using the sheet first I can press and remedy gaps with the second layer (stings as it's alcohol based) paste and that indicates I've covered the gap. Before it would sting like hell all around and wasn't covering as the final appliance hides things. Before I sort of justed winged it and hoped for the best which often needed to be replaced.
It's a more lengthy two step process however it's better at covering the skin around and protecting it from the acid based output which irritates the skin and makes ones life uncomfortable.
I'm also getting 3-4 days out of a bag now more frequently than just paste and appliance alone. Skin around is better condition as well.
Apply extra adhesive seal all around and a belt.
I use a one piece convex and use a bottle of water + mountain wash to rinse.
What an improvement..