You can electrify your coop- give them 12hrs a day of light, reset their internal egg clock for spring- and they will start laying again. If it is the shortened days...
If they look scraggly and have lots of pin feathers, you will just have to wait until they stop molting- all of their energy is going into making feathers.
If you have some broodies- you will need to wait a month (or two) until she gives up, or 'break her up' look up breaking up a broody hen. Then wait a week or so for her to start laying again.
Winter is their natural down time, lots of people take advantage of this too- and do the dewormings during the no egg time.
Or get some leghorns AND light up the coop for lots of eggs in winter!