If you go the whole hog, you can install proper security cameras and keep an eye on your outhouses with an app. Alternatively, you could put up fake cameras to deter burglars as most won’t know the difference.
Be careful not to leave out any tools in your garden that thieves could use to help them. Spades, forks and ladders should be properly locked away when you’re not using them. Protect your home itself by making sure you have secure windows and doors. Personally, I have Everest windows with a GrabLock system to make them extra secure.