I am going to create a widget.My question is how we can skin that widget so the user can easily integrate that in his/her website without changing the existing look and feel of his/her site.
Looking for your valuable suggestions.
I you are creating WP
I you are creating WP plugins, widgets then you need to be aware there is very little styling that you may add, other than essential styles to manage layout aspects - visual styles other than that must be handled with care (which is kind of what you are stating)
Not really a question we can help with in any great sense this is a coding forum and this is specific WP plugins/widgets. I would suggest though you try your widget out against as many themes as you can to see how it sits with them, easiest approach really.