A handy list of appropriate Stage 1 baby foods (and any baby food, really) can be found at Wholesome Baby Food. With this list, the list our pediatrician gave us, and common sense, I have made determinations of what I personally feel comfortable feeding the Test Nommer.
The common sense I'm using is: 1. Is it acidic 2. Is it something people seem to be allergic to a lot 3. Do we have any issues with it
If the answer to any of these is yes, I'm holding off on it.
We also follow the 3 day guideline, where we give a new food, and only one new food, for 3 days in a row to check for reactions. We could go to 5, but we usually don't. I'm impatient.
Tip #1: Mashing slick stuff
For banana and avocado, I had a rough time mashing these really smooth by fork or spoon since they don't need to be cooked. Since I mix the fruit with cereal anyway, I pour the dry cereal onto the partially mashed fruit and then mash to a very smooth puree and add water (or formula) to thin it out to the proper consistency. It's a similar method to adding kosher salt to minced garlic to make garlic paste. Only baby appropriate. It's culinary sandpaper. But I digress.
I haven't tried this method with regular gerber rice cereal, which dissolves very easily, but it should work the same. I have been using Earth's Best Organic Brown Rice cereal, and it takes a bit longer to absorb liquid so it works well.
Tip #2: Freezing cubes and storage
As mentioned before, I use regular old ice cube trays for freezing the food. The plastic ones you sometimes have to beat on the counter to release ice cubes, the ones that you have but have no idea where they came from.
The key to releasing the food from the trays is to only leave the trays in the freezer a few hours to JUST freeze the food. It'll take less time than water. As you release them, put them in a ziplock freezer bag and date and label. And there you have it! Convenient 1oz portions of delicious puree to be mixed and matched with other delicious cubes.
Tip #3: Reheating Frozen Cubes
This is not the most environmentally friendly way to reheat, but, it works. I boil some water in the microwave, then I put the cubes in a sandwich bag and put that bag into the hot water, and in about 5 mins its defrosted and ready to go. If I'm in a hurry, I'll put the bag into the water before it goes in the microwave. I don't straight up microwave the food in a bowl because it's such a small amount, half of it bubbles and gets gross before the rest of it is even defrosted and it bugs me. It probably doesn't help out the taste or nutritional content, either.