I came up with this simple method to make a workbench when I was in need of a new one and didn't want to spend a lot of money or time. It has served me well and it can be build in a couple of hours.
Step 1: Basic Build
What you need
Top and a bottom of workbench. I used a table top that is 1-1/2" but you could use 3/4" plywood doubled up as well
2 bookcases. Flat pack models from most big bog stores will run about $20-$25.
4" casters Pick a type you like, but locking feature will be nice to have
Handful of wood screws.
1: Install the casters to your 2x4's and then attach the 2x4's to the bottom piece of bench.
2: Lay out 4 2x4 pieces cut as wide as the bookshelf. You can screw these down or add glue.
3: Set out and align bookshelves. Drive screw through bottom of bookshelf. I used a screw long enough to go through the 2x4 as well and attache to the base.
4: Add top and align. Screw though top of bookshelf to underside of top.
Basic Bench Done
Step 2: Customize
I've customized my workbench over time. If you look for a bookshelf that has at least 26" wide shelf and middle chest tool box will fit perfectly.
Step 3: Complete and Ready to Customize
You can customize you workbench to fit your needs. After a couple months of use I realized a power strip would be nice.