1. Write program longhand, on fanfold paper (more on this below).
2. Type program on cards. Those IBM 029 keypunches were the loudest, stiffest, most satisfying keyboards ever. The Model M is silent and squishy, by comparison.
3. Take cards over to reader. Deck is read, often without problems.
4. Go over to the lineprinter, and wait, with everyone else, for your output, printed on fanfold paper. This stuff flew out at a few feet per second.
5. Collect your output, debug.
6. Implement your fixes by deleting or replacing affected cards, and typing new ones, making sure everything goes in its right place.
7. Repeat from step 3.
Often the wait for your output was long and excruciating.
Fanfold paper was FANTASTIC scrap paper. I had so much of it, and used it for everything.
Every card reader/lineprinter station had an operator to deal with the inevitable jams and other problems. They would often get approached for programming help. One particularly cruel joke: "Oh, that's a color code error. You typed your program on the wrong color cards."