Just to clarify iflyer's post, there are no "go-to guys". The contract dictates who flies the trip, not CS secret friends lists. NEVER EVER answer the phone. Ever. In a short manned category you will have your pick of the litter when it comes to trips, why fly whatever garbage CS happens to have up on deck. Always watch daily trip coverage in a short manned category, if CS tries pulling some crap (which they will do) then you have a contract to protect you. Nothing like getting paid for somebody else to fly a trip that you should have been awarded

.
When CS calls your 1st phone login to icrew and check the daily trip coverage. If GS aren't in high demand then you'll probably take anything. If they are flowing like they were on the 717 this past summer make a decision if you like the trip or not. Then when CS calls your 2nd phone you can pick it up and accept the trip (or just wait an hour for the next call...). Once you pick up the phone you are obligated to take the trip unless you can't make the commute, have child care issues, or have been drinking.
If the trip is >2 hours from sign in they will typically put the trip on your line and you can just accept it in icrew without ever picking up the phone. This can back fire in 2 ways: 1. There are lots of trips available and you need to call them back to tell them what you want. This is a problem because calls to CS can easily go unanswered for 25 minutes. They only have to hold the trip for 10 minutes so the one you want could legally be gone before they pick up. 2. If report is within 2 hours they don't need to give you 10 minutes to reply. This is why I check icrew immediately upon seeing the caller ID for CS. If the trip is good and within 2 hours of report, you have to pick up the phone or it is highly likely the trip will be gone before CS ever picks up your call, and quite often the trip will only be on your line for a minute or two, if that in icrew.