Since September 30 there have been eight burglaries in Market Deeping and Deeping St James with items including handbags, laptop computers, satellite navigation systems, digital cameras, mobile phones, MP3 players, mountain bikes and wallets with cash being taken.
In many cases thieves got in through back doors or windows which had been left unlocked.
Now police are advising people to be extra vigilant by keeping keys and Christmas gifts out of sight, closing curtains and locking doors and windows.
Police community support officer Karen Dobson said property marking pens were available free from Market Deeping police.
She said: "Before settling down for the night make sure all property is out of sight and secure.
"Property marking, recording serial numbers on the Home Office Coded for Keeps website and displaying window stickers saying this has been done are useful deterrents."
Anyone who wants advice can call Karen on 07944 776990 or community support officer Christopher Clarke on 07825 100362.