Reading through the new CCDP book, I came across an interesting fact. Turning off trunk mode negotiaion (switchport mode trunk) and DTP (switchport nonegotiate) can reduce the link transition time by 2 seconds!
Further, it is good to put your most important vlans as low-number vlans, because they are first to come up. This can save probably miliseconds rather than seconds but it’s still a timesaver.