This is a fantastic recycling idea for an old T-Shirt for a more eco-friendly trip to the market.  

Supplies
Old T-Shirt
Rotary cutter or scissors
Ruler
Disappearing ink marker or Sharpie
Sewing machine

1. Get supplies together.

2. With the help of a ruler, mark sewing line of the grocery tote on the edges of the T-shirt with disappearing ink marker or Sharpie.  It will be turned inside out when complete, so any Sharpie markings that don't wash out will be on the inside. 
 

3. Sew sides and bottom marked edges. Leave top open.  Use straight stitch or zig zag.  I rounded the corners on this one.  Backstitch at the start and end of the seam.  Trim sewn edges.  Cut top edge at drawn line.

4. Mark 2" long lines with a ruler every 2", starting 2" from the bag bottom. Stagger the openings each row so they alternate. Leave 5" from the top for the handle, marking one large 5" horizontal cut in the middle.

5. Cut marked lines with rotary cutter or scissors.
 

6. When finished cutting, double check the opposite side of the bag to make sure the line has cut through both layers of the T-Shirt. Extend openings if needed with scissors. The size of the openings and distance each row is to another determines the final look and how open it is. Turn inside out.

7. Throw in the washing machine.  Wash and dry and extend the cut openings as many times as you need until you get the look you want. Tight-weave T-Shirts work best. Experiment with different color T-Shirts.