If dreamed you that you wear an antique dress with sandals, in real life you sharply feel need for harmony with yourself and world around. For the young woman the dream in which she cannot clasp thongs on sandals in any way, warns her that she stepped into a slippery slope. While the getting is good, she should be convinced once again that it will have enough forces to pass it. The dream in which to you rubbed feet with sandals is adverse.
Summer, or a summertime mood
Relaxation or casualness
Coolness
Vulnerable or exposed
A setting or timeframe you associate with sandals
Also, consider the context. For example, wearing sandals to a formal workplace may represent a fear of being judged or seen as inappropriate.