I use a product called Un-du. Works like Goo-Gone, but does not leave an oily residu. Also, this product is great for lifting things that have been glued slightly crooked. I have been using it for years and have never had any trouble with it leaving a ring or showing after it is dry. After the paper dries (very quick) you can simply stick it down again, usually without more glue. Also does not harm photos if you decide to move them in scrapbooking. Love this product.
I second the recommendation for Un-du for removing items that have been glued on crooked (or occasionally upside down! LOL) I couldn't make cards or scrapbook without Un-du! I haven't used it for my scissors, but I'm sure it would work perfectly for that as well. For removing the sticky tape residue from my scissors, I typically grab a packaged alcohol wipe - I always keep a box on my scrap/stamp table.