If the pieces are in their proper positions, the case should close securely but easily. The mouthpiece will be placed in the case with the ligature on it, and then the mouthpiece cap can be placed over both, with care being taken not to nick or crack the facing of the mouthpiece by hitting it with the cap. I prefer plastic caps for this reason. It is healthier to take the reed off the mouthpiece before storing it. Reeds left to dry on the mouthpiece can warp, so that it will cause them to play badly in very little time. However, reeds left floating in the case will most definitely be broken to boot. To give protection to reeds, store them in a reed guard of some kind that will keep them flat. Wet reeds kept in the paper cases or boxes during which they were sold will not stay in good playing shape, as they aren't capable of dry in a flat position. A good reed case may be made of a hard cloth plastic or with a tumbler plate, will offer protection to the end of the reed and will keep the reed held securely on a dry, flat surface. The clarinet should be kept free of dirt and grime by dusting under the keys with a soft brush on a standard basis. To keep keys moving correctly and noiselessly, apply a small drop of especially formulated key oil where the key rods meet the posts.