Does anyone know any sneaky ways of getting the gears 1 and 2 achievements easily to unlock the gears 3 skins? I know if you have a person that has gears 2 achievements you can use a glitch to get them for yourself, but is there an easy way of getting 'domination', and the one where you have to get the highest score in a gears 1 ranked match etc?
If by sneaky, you mean obtaining through not so legit means, then you would have to risk your account and Xbox to do it.
There are programs out there that can add achievements to your account but doing so is risky. I do not condone tampering/hacking/cheating so I will not link you to these places.
However, the other meaning of sneaky would be a glitch that gives you the achievement. As far as I know this doesn't exist.
You could always, you know, play GoW 1 & 2 and earn these achievement. If you do it this way, you will feel a sense of accomplishment rather than if you just got the rewards without doing anything.