In some aspects, the present disclosure relates to methods for treating, preventing, minimizing, and/or diminishing signs of aging in the skin, such as facial wrinkles, and for training a user's face to favor some configurations or expressions over others. A gel or other viscous liquid with specific properties may be applied to areas on the face or body, that may change state to a thin, adhesive semi-elastic transparent film that is left on human skin over a period of time. The properties of the gel and the method for its application on the skin are carefully configured to for instance optimize the sensation (or force) feedback to the user in response to the user's conscious and sub-conscious micro-muscle movements, to discourage use of specific facial muscle groups, reduce or prevent wrinkles, and/or achieve a different repertoire of facial expressions, or for other self-improvement reasons.