This was something I picked up in 3x.
A sneaky little tactic that works wonders if a 'few' people do it.
Its basically naked binding.
(Sorry if this has been posted before)
Sure if you naked bind in normal clothes, you'll be noticed.
However there is an outfit out there that does 'sort of' look like you're in full rune. Sure naked binding isn't going to give the same magic att bonus as with robes, but if you're level 100 and want to bind, yet hide half effectively, i'd use this technique.
Firstly, change your character to female (south of falador).
Next, go to the clothes shop in varrock + change your outfit to the below.
High detail -

Low detail -

It kinda looks the same as having a rune chain and plateskirt on. If a sniper is quickly looking over a pile, he won't notice you, if a lot of other people are still in robes. Its not until he looks hard enough, does he actually notice that they're your natural clothes.
For the hat, you 'could' change your hair to some variation of blue that 'looks' like a rune full helm. You might be able to get away with wearing rune helm (-6 magic bonus), or swap it out for a wizard hat. It'll make the appearance a bit more noticeable with wizard hat, but you won't have the negative magic bonus.
Only bad thing to this is you're going to have to switch to invy to take off your clothes. But if you're honestly terrified of binding, try this, see how it goes. Once you're comfortable with it, you'll be more inclined to wear normal robes.