Long-Term Storage of Equipment

I will have to box up speakers, Amp, digi-players, and a turntable for several months due to a temporary move.

Apart from temperature-controlled storage, what can I do to make sure that all is well?

I'm thinking about those "silica" packets that we've all seen in new boxes. Apparently it does something regarding humidity...

Any thoughts on whether this is something that I should chack into?

Any suggestions appreciated.