How snug should a compression garment fit?

Your compression garment should be moderately tight, but should not constrict your movement or hinder your breathing. I would recommend talking to your surgeon and see if you can exchange it for a larger size.

There is no evidence that compressive garments influence the final outcome after liposuction. In the short term they are primarily for comfort. There is no reason for them to be too tight.

A garment should not be so tight that it restricts you movement or breathing.  Best of luck, perhaps you need a looser garment.