Never lend out any of your magical equipment, spell books and so on as it is a racing certainty that (a) you won’t get these things back and (b) you’ll inevitably lend them out to the “wrong” people. “Wrong” as in totally evil beings who merely wish to disarm you the easy way.
What to Do With Strange Objects
If you find an object lying around – say a sword in a block of marble – don’t touch it. It’s almost certainly meant for somebody else. Unless you really are Arthur Pendragon and let’s face it the odds are against that scenario. Also look out for those who leave objects around. They are either careless or setting a trap and you don’t want to get caught out by either of those scenarios, do you?
Is Sanctuary All That It's Cracked Up to Be?
Always find out who runs a place before you visit it yet alone consider it as a place of sanctuary if the Ringwraiths are after you. Look out for those in debt, those with known weaknesses and those of dodgy character as these are the ones who will betray. Make friends, not enemies.
Origins of Food and Drink
Make sure you know where your food and drink comes from. Ideally take enough of your own to see you through. Always have the latest edition of the map on your person. Never leave it in a rucksack. These things have a nasty habit of going missing – and sometimes the person carrying the rucksack does too.
Relationships with Other Magical Groups
Don’t cross the Fairy Queen, don’t cross the wizards, don’t cross the witches, don’t cross the fairies – that way you can at least avoid being cursed in various imaginative ways! The only cursing to do is your own!
Respect
Treat the elderly with respect – you never know who they’ll turn out to be. Treat stepdaughters well – if things work out for them later, they may well remember you. See it as the Buttons Principle!
Being Observant
Always look behind you! Always look in front of you – and don’t forget to look to right and left and up and down as well as enemies in the magical world can and will attack you from all directions. If you’re prepared for strange creatures to “have a go” you’re less likely to be attacked by them. Nobody likes a surprise ruined.
Ensuring You Use Magic You Can Actually Handle
Don’t meddle with forces that are beyond you. This particularly applies to lazy apprentices who want to take a short cut with the cleaning. If you come across strange objects (sword in stone, crystal ball apparently abandoned and so on), leave well alone. These things are the source of much trouble. Do you really want that?
Interfering
Unless you want an early death or are Eileen, do not poke your wand or other magical implement into anywhere it is likely such interference might lead to a break out of war. If you are Eileen, the usual rules don’t apply. If the former applies, you need help fast! Incidentally many a magical death has occurred because wizards in particular suspect anyone poking their nose in of trying to steal their powers. The only way to convince them otherwise is not to meddle.