You feel jaded, fed up of writing the same old stuff. You realise that you re-use plots and techniques, that you're writing self-parody. So you decide to experiment.
I sometimes write things I neither like nor understand. Maybe my powers of criticism and appreciation have fallen behind my imagination. Maybe what I've written is a Hopeful Monster, its stubby appendages the wings of future generations. Maybe what I think is unfinished (a mere sketch or draft) can be treated as a finished work (there are precedents for this in Art and Evolution). Time and amassed criticism might eventually conclude whether the pieces are dead ends, indulgences, Ugly Ducklings or discoveries.
Though I liked Jon McGregor's This Isn't The Sort Of Thing That Happens To Someone Like You (with its deletions, repetitions, one-sentence stories, etc) less than his glorious So many ways to begin, my admiration of his work didn't lessen - it's good that he tries new things out. Ditto my reaction to Tania Hershman's more recent pieces in "My Mother was an upright piano" - reviewed by Jim Murdoch. Readers need to learn how best to deal with these pieces, perhaps coming to some kind of concensus. For those of us with far fewer readers and less time, evaluation of our non-standard pieces is hard. I tend to pass the buck to magazine editors.
Of course, what's experimental for you may be old hat to others. Maybe you're escaping from private clichés only to indulge in public ones.
Personal affectations are what help identify you, they're part of your personality, your voice. If you start exploring without the means to assess what you're doing, without awareness of what others have already done, you might end up lost, with only a pile of rubbish as proof of your efforts. Public fashions and mannerisms can constitute a style (e.g. Mannerism). Avoiding fashionable traits may merely tempt you to use unfashionable ones, or to use plainer language (itself a trait).
Awareness of one's habits and of contemporary fashions is probably a good idea long term, though it can be stultifying at first. Using these features consciously and judiciously should be our aim. As Eliot wrote - "We shall not cease from exploration And the end of all our exploring Will be to arrive where we started And know the place for the first time".