The chair, warm cloths, comfortable placement of eyepiece and finder as well as bug spray and dew control are all discussed. I'll speak for efficiency only and the top 3 things that I find great for the field.
Numero Uno Efficiency Tip:
Telrad sight and a planitarium program that shows telrad patterns. OR better yet is pre-printed out charts with telrad patterns on them and then a close in field (40 minute across) for star-field confirmation. (I assume no goto because you might enjoy the hunt like I do). Telrad is a #1 ticket to efficiency (if you have no setting circles). If you do use goto I suggest some of the time on easier to find targets try it with telrad and this will help you when your battery dies ...
A second key tip for efficiency:
Two or three eyepieces with one fairly broad one for initial finding and one or two of your favorite higher mag eyepieces so you span a range of magnitudes and here is the important bit ... All three must be right with you while you are seated. This can be done with an eyepiece rack mounted on your scope in a place where scope position does not cause them to fall out

I also like a waist pouch for eyepieces and keep 5 or so right there on my waist for fast access. If you are doing some messier marathon or out for absolute max targets per night consider a 20 to 8mm zoom (loose quality but gain speed of acquisition/viewing).
Tip #3 that you may have never even considered yet I love this one:
When working a specific area with several targets you want to veiw (like Markarian chain or galaxy clusters) I have found a sturdy music stand to hold my chart with magnets on the metal music stand invaluable. I use that to hold charts OR my light netbook with MegaStar planetarium and a red LED gooseneck lamp to see the charts. Plus a pencil. EXTREMELY handy as you can set it up like a table or have it angled depending on netbook use or just paper OR even your insulated cup of hot drink.
Gotta throw in my bias on efficient scopes too:
Oh, and my scope preference for absolutely fastest setup and tear down and target acquisition for medium aperture for folks early on in aperture fever stages is without question a 10 to 12" Dob and an adjustable chair. 5-minute setup/pack, done. Mega-efficient on setup time for medium aperture scopes with no need to find polaris and no need for battery and cables. Sweet.
I don't know the budget but for efficiency on the above mentioned dob solution digital setting circles with something like Sky Commander readout I use a lot on my big Dob for re-observations or targets that are far away from visually detectable stars (for telrad find). This too is about efficiency VS thrill of the hunt so you don't have to use it but it is there when you want to view large numbers of targets (I recently re-observed most of the herschel 400 list for example and did not want to re-find all of them manually). When I was in Australia a year ago all I had was a Telrad and finder on a 12" dob and I was having a blast finding hundreds of the great southern sky targets I cannot see from my +36 degree North location.