Home made baby food?

My son in 6 1/2 months old. He has been eating Gerber food since 4 months and has started on stage 2 for about a month now. I have noticed that alot of the stage 2 foods are watery and I feel he is ready for some mashed foods. I was going to try making my own squash, carrots, and mashed potato. I have a steamer and plan on steaming them. Do I use the left over water to make them somewhat thin? Also how do you store them? Is freezing them in ice cube trays and then transferring into a plastic container the best way? And about how long do they last? any help is appreciated as I am a first time mom.