What's the best route when on a bad run? Take a break, play tight, play less aggressively?

Taking a break would be my number one advice. Enjoy your other hobbies, catch up with friends etc. Poker is a game of when it rains it pours in terms of variance. Study a little more, make an effort to discuss hands with others and review spots you're not sure about.

When you do decide to take to the felt, particularly online, cut out your tougher mtts and lower your variance. This gives yourself the best chance of winning and breeding confidence.

Well I think you should give your game an and honest evaluation. Are you confident that its just a bad run and not that you might have developed some bad habits that are costing you chips? We all do it and need to constantly re-evaluate what we are doing. If you are happy with the moves you are making (I assume you feel you are having a bad variance cycle) but just being drawn out on, then I would count on the odds catching up and just play through it.

But really look at your game and make sure you are playing with solid values, and that you are not staying with losing hands to long. If its online with a HUD its easy enough to run some filters and look at all the hands you lose X number of BB's. Live play is obviously harder to sort out, but you should be able to remember the hands that you lost a large part of your stack with.