I usually make concasse.
With a knife, carve an X into the top of each tomato. Drop into a large pot of boiling water for 20sec or so. Immediately remove them to a bowl of ice-water for 30-40sec, then peel the split/separated skins off.
Next I trim the vine end and halve the tomatoes. I pull out the seeds/membranes, and then dice the skinless/seedless flesh into whatever size I want. Takes a while the first couple times you do it, but then it just becomes routine, right down to washing the pot as the tomato skins contract in the cold ice water.