Wash and dry the tomatoes.
Remove the stem and core (if desired).
Cut tomatoes into fourths (or smaller), slice, or chop (if desired).
Place on a baking sheet (or other firm surface), skin side down (if applicable).
Freeze for at least one hour.
Place tomatoes in freezer bags in a single layer, taking care not to overstuff the bags. (See notes for other container options.)
Remove air using a vacuum sealer or the straw method.
STRAW VACUUM SEALER METHOD: After filling your freezer bag with your frozen tomatoes, flatten the bag on the counter. insert a straw halfway into the bag. Zip the bag shut as much as possible while forcing as much air out of the bag as possible. Suck the remaining air out of the bag until the bag shrinks around the tomatoes. Quickly remove the straw from the bag and seal the bag.
Store the bags flat on top of each other in the freezer.