Where to start on this, that is the question facing you? These paints tend to collect extra specks of dust etc. There is no getting away from it, they are not really too easy to work with, being made of a smudgy consistency.
It is worth bearing in mind that pastels can do you harm, as the pigments will pick up dust particles, which can in turn be inhaled if you are not careful. So it is hard trying to save your work.
Acid free tracing paper is one thing you can use to cover your work, available sometimes in stationers, as well as art shops. Newspaper too can be used to store, however, I would be too worried about the print and acids used for these to do this.
Now you can obtain boards which are acid free, so if you intend to try and store your picture for a long time then I would attach it to a board using masking tape and cover it with tracing paper or even greaseproof paper or tissue. Just remember to strap it down with a tape of some sort.
When you reach the framing stage, decisions have to be made. At this point you may decide you would like to change it somewhat. Maybe you think it is improved with less sides for instance or even all the way round.
Even a few inches can sometimes make the difference. A good way to decide upon this, is to have a frame made of card which you can look through at different angles. This way you often may decide to go with less in the frame.
If you want to put your work in a glass frame make sure that you have like a cardboard mat over the sides of it, as you do not want it touching the glass. Never have your work next to the glass with pastels. Otherwise you are likely to get condensation and get dark spots on your work.
If you frame it with the mat no problems should occur in the years to come, even without fixing it. This does not mean that you cannot fix it! Spray it with an aerosol by all means, but be careful not to inhale some of the strong fumes.
Fumes can be very dangerous to your health, so really, if possible, it is better to spray outside, depending on the weather of course. Not that I always do, to my shame! Please, if you spray inside at least open all the windows.
What you really need to do is to buy a plastic mask which will cover your nose and your mouth for this. Particularly if you suffer from allergies, as pastels collect dust and are also quite messy.
It is quite possible otherwise that your nose will get all stuffy if there is not much air in the room, so this is a word of warning. As I said previously when you work with pastels they do tend to make a mess of your hands. I find that I take quite a few breaks for coffee, just so that I can give them a very good wash, before I continue.