Step 1: Label Freezer Bag
You've got a ton of fresh tomatoes from your garden or from your quality local supplier, have roasted them, and need to store them for the winter.
Acquire a box of heavy-duty quart freezer bags. You want to be able to thaw the tomatoes in one-use shots, so don't go for bigger bags unless you're into seriously large-scale cooking.
Label and date the bag with a waterproof marker before you get started, then flip the top inside out to avoid getting goo in the zipper opening. Cook's Illustrated says that regular zip bags work better than the ones with slide closures, and the thicker the bag the better. Thicker bags block evaporation better, while bags don't seal properly directly under the slider.
*It's very important to label and date your freezer bag. Years from now, when your grandchildren chisel this out from under layers of ice, they'll want to know whether this bundle requires special hazardous waste disposal. It will also save costly carbon-dating.
Step 2: Fill Bag
Scoop those tomatoes right into the bag. Note that the spoon makes all sorts of contact with the inside top of the bag- thankfully you've folded the top inside-out and won't have any goop in your zipper or on the outside of your bag.
Fill it until you reach ~2/3 or the label line.
Step 3: Remove Air and Seal
Flip the top back up, squeeze the excess air out of the bag, and close the seal.
The bag should lay nicely flat. If it's still all bulgy you've overfilled it, and won't be able to stack it properly in your freezer. Reallocate and continue.
Step 4: Freeze
Now stack it in your freezer, and wait for good tomatoes to again disappear from the earth. You've cornered the market, and will be able to enjoy tasty roasty tomatoey goodness during the long cold months ahead.
You'll be extra happy that you're storing roasted tomatoes, since they've already dropped most of their water and will take up much less freezer space than fresh frozen tomatoes.