I go for easy, I freeze. Freezers run under $200 to buy (I'm not sure how much to run; I think mine was estimated just under $30 a year).
Tomatoes I blanche (brief dip in boiling water then move to ice water), skin, chop, bag.
Onions and peppers I chop (I do a variety of coarsenesses for different uses), lay out on a cookie sheet to freeze, then transfer to a freezer bag.
Squash I cut into bite-size pieces and bag (for soups and stews) or puree and bag (for hiding in spaghetti sauces and chilis so my husband will eat them
). The texture's not good enough for use in veggie fajitas and such, but it's good enough for the uses above.
Raspberries and blackberries I just wash and bag; maybe cut them in half if they're big.
Strawberries and peaches I slice small and bag. Texture isn't like fresh (adding sugar helps with that), but they're very good in cereal, frozen treats, and such.
Greens I chop very fine and bag. Again, I hide these in sauces.
Corn on the cob I blanche and bag.
Cabbage I cook like I want it in the crock pot and bag in single serve portions.
Last night I froze a bunch of herbs; just washed and froze as whole leaves. I plan to use them as if fresh, but this is the first time I've tried it.
Is there a useful way to preserve cucumbers without making pickles? I think I'm about to be overrun by them...