This used to be me.
1. A good knife - sharp, holds a blade well.
2. Practice. Then practice some more. It took me several months to really get good a chopping an onion efficiently.
3. Mandolins are amazing. We love them for winter salads, too, because we can quickly slice up 4 kohlrabi, some carrots, and an apple. Or if we want to make a large batch of pickled onions. (I hate raw onions, but love them pickled. We make 1-2 gallons of quick pickled red onions at a time - no processing. They are amazing in salads, tuna salad, on sandwiches, and so on).
4. Some types of peelers are much faster and more efficient. My little black n decker one is far better than others I've had to use. Start at the top and peel down - it should slide easily.
5. Broaden your idea of the salad - especially for winter. Indian and italian cookbooks have other types of salads than the classic lettuce salad.
6. Now is definitely CSA sign-up time in Boston. I just signed up for one that should be almost all of our veg (we are 5 going on 6), for only 30 week. Organic, local, delivers to my neighborhood so I walk to get them.
7. Practice. I used to time myself so I could see if I was getting faster.