It depends on what circuit you are working on. There is no thumb rule for that, however, in general, capacitors are associated with frequency or noise of the circuit. First you have to go with some theories like Filter capacitor, low pass, high pass, band pass, shunt cap, etc.
Depends upon the use in circuit, and also rating of capacitor matter, don't use a capacitor with low voltage rating at high voltage. any capacitor has two values first is its farad rating and second is voltage. Generally RC value decides the characteristics of circuit and we fix the value of capacitor and change the value of resistance as variable resistance are available but varicaps are costly, so use any capacitor value and accordingly change resistance. this works in most application