The meaning of a dream featuring garters depends entirely on the action and is as follows:
If your garters were unfastened, it is a warning of danger from bad companions.
To lose a garter indicates coming trouble, but if someone picked it up and gave it back to you, you can expect help from a friend; however, if it was not returned, your problems will be compounded by unexpected treachery.
To dream of finding a garter is a warning that you are currently skating on thin ice and you would be wise to alter your course before you go through.... The Complete Guide to Interpreting Your Dreams