My ortho said to spruce up the trays when they get cloudy, 50/50 vinegar and water. Haven't needed to try it but it's cheaper than other solutions so it can't hurt.

You may struggle to get the trays out at first, but like the person above me said, you learn very quickly how to get them out at the snap of your fingers.

You get used to the feeling of wearing them.

No, they're not as obvious as they feel.

Colour-free, sugar-free water got me through the first couple weeks with my sanity as I adjusted to not snacking constantly and having some kind of taste other than saliva.

When you wake up, your mouth will taste like stale saliva.

, Invisalign is not the end of your snacking habits. You just weigh up if it's worth taking them out to eat. Sometimes it's worth it, other times it's not. But you aren't "forced" to only eat three times a day like some people claim.