I'd say the biggest ways to reduce inputs into sheep are -
Better sheep - Less problems and faffing needed, reduces labour input, reduces medical bills, reduces feed needed, improves lambing percentage / weaning percentage etc etc.
Better pasture management - A greater number of sheep can be carried on the same acreage, increasing profit per acre and profit per ewe, ewes and lambs require less (no) hard feed, lambs are finished are away quicker.
No (less) hard feed - If you get the above right, you may be able to totally eliminate hard feed, which would be a big saving.
Having said all of this, the most important thing is knowing your costs, because unless you know those inside out. . . . you can't change anything meaningful!