So I don't know if I can explain what I have been doing but I will try.  I have been doing this to  strawberries and regular head lettuce mostly as soon as I get home from the store.  Any fresh produce seems to last in a vacuum seal longer.

   I have been using quart or gallon freezer bags with a double seal. Find a heavy duty straw.  Put produce in bag.

  Press seal together from one side till almost closed.  Put straw in corner of freezer bag that is still open a bit.

  Hold the seal tight against the straw on the one side and suck all the air out of bag by taking a deep breath on the straw.  Continue pulling air out and pull straw  out of bag as you push the last bit of seal together.  A Human vacuum machine.  Strawberries stay good for a week or more.  Re-vacuume the bag if you use some or it looses its  vacuum look. Mostly if it is a little warmer then the refrigerator when you vacuum seal it the first time.