The keys to repelling thieves from attempting to break in to your home is to make it difficult and increase the risk of them getting caught.
Make it look like there's someone home even when there isn't.
Leave lights on. Use timers if you want to save electricity during day time.
Leave a radio on.
Ask a friend or neighbor to empty your mailbox.
Ask a neighbor to park their car outside your house.
Have someone clear away snow in winter.
If possible, have someone live in your house while you're away.
Make it difficult to break in undetected
Lock all doors and windows.
Install movement sensitive lights around your house so it's hard to walk around undetected.
Install a burglar alarm.
Hide all small valuables, like jewelery, cash, credit cards and phones. Don't hide everything in the same place. Scatter it around the house.
Install good locks on all doors so thieves are forced to enter and exit through windows.
Activate code locks on phones, tablets and computers.
Make copies of important things
Back up computers so there is always more than one copy of everything. Preferably back up to another location in case the house burns down.
Scan all paper photos and important papers.
Photograph all belongings, particularly valuable ones, to be able to prove to the insurance company that you had them. Save receipts if possible (scan them).
Get an insurance for your home.
What are your best tips for avoiding burglary and theft? Post them in a comment.