Right now is a really good time to start some new beds. The grass is mostly dead and not too much else is going on in the garden. We do not need any new beds right now, so we are fixing up our old ones. We spread almost done compost and leaves over the beds. This will decompose in place fixing the soil for our spring veggies.
If you are starting a new bed, winter is a good time to use the lasagna method for building a new bed. Hot tip: Using a garden hose or bag of flour, you can mark off the outline shape you want the bed to be. Then you can check out how it will look before you start the hard work of digging. Dig out the grass. Which should be easy now that it is dead. Put down plain cardboard and wet it with the hose. Then pile compost and leaves on top. In a few months, your grass should be 100% dead underneath and the soil will be in good shape for your new garden.
We are switching to a keyhole shape in our veggie garden. We formerly had simple rows. The keyhole is a staple in permaculture gardens. It offers more gardening space with the rows still easily reached by the smaller path area. The path looks like a straight line with a circle on top. (hence- the keyhole) We used cuttings off our Christmas tree to mark the new path area.