My wife was a stay at home parent for years and a couple of things we did during this time to offset the secondary income loss, were pretty cool and helped us alot. The first thing I did is I changed my exemption status on taxes. Even though I was able to claim up to 5 exemptions this did a couple of things to help us. First, it was sort of a way of saving without actually seeing the money that was sitting in account, that we might have used had it been readily accessible. Secondly, instead of making payments for home improvements we used our tax returns, which was a sizeable lump sum to try to do an improvement a year or catch up on anything that might cost us interest and pay it off early. We also have purchased our vehicles when we could get 0% interest. This is a very big advantage as well.
I was also privileged enough to have a company car and get some expenses paid for. Even though I paid my expenses with a rewards card and earned cash back (1%) on the card, I did not put this all towards the credit card bill and instead used this cash for petty spending and not putting more debt back onto the card.
Now that the roles are reversed and I am home my wife is selling all of our children's clothes that they do not use anymore. Although this may not seem like a lot it is a cost savings to get some money back from the clothes. I have also utilized all of the available resources from school financial aid and scholarships. I highly recommend applying for scholarships as these make a huge difference. In the two years I applied I was fortunate enough to be awarded a total of $2,750 from two different scholarships. This is a huge deal to offset costs from school. I also don't mind Ramen noodles and this helps =).