Okay, so sometimes the 2nd Oboe has to sit for quite a long time doing nothing…
…which is all well and good until you have to come in quietly after a long break, as here in Mussorgsky’s Pictures at an Exhibition:
E to C# in the lower register after a lengthy tacet? Thanks very much. But there is a neat trick you can perform to make this entry slightly easier. The problem is that your reed will have dried out and opened up a little, so you need to get it ready to play again. Take the reed out of the oboe during the tacet, and, if you have a water pot with you, give it a little extra soak. When the moment of your entry is drawing near, do what you do when making reeds to ensure that the reed is airtight: namely, place your finger over the cork end of the staple, form the embouchure and put the reed in your mouth. Pull the reed out so that it makes a little popping noise (if there’s no pop, the reed isn’t airtight). Repeat two or three times*. This will have the effect of closing the reed up slightly, so it doesn’t make a honking racket when you come in on that E.
It works, I promise.
*Obviously don’t do this in the silence between movements! By that stage, you should have the reed back in the oboe and you should be watching the conductor, because you have to pick up the speed of the movement quickly: there are only seven beats before you come in.