A bike thief is going to be thinking of 2 things:
- How appealing your bike is. Make it less appealing with tape or a bad respray.
- How easy it will be to steal. A d-lock is harder to break through than a chain. If you want to make it even more of a pain in the arse to steal, take the front wheel off and bring that inside with you.
If your bike looks worse, and has better protection, than bikes around it, it should be relatively safe.