If you are committed to getting all your customers remote ready with a pigtail then putting a few items together to take to the controller each time speeds it up. If it was a first time call, after introducing myself, I would ask them to give me 15 minutes and then I'll come get them. Keeping the customer from looking over your shoulder and asking questions makes the hookup go much faster. It is a lot easier to sell the pigtail after you've shown the customer remote servicing than trying to explain it while installing a pigtail.

The tools I kept in a group to speed up the hookup included:

Stationmaster or voltmeter to check all the zones to make sure all the solenoids are good. Then I would determine my 24vac for the blue/white wire on the pigtail.

A small power screwdriver with long phillips and straight slot tips to loosen and tighten the terminal screws as each wire was put on. 

Keep a drill bit just larger than your pigtail strand to drill an entry hole at the bottom of the controller to push the pigtail into the controller. After pushing it in use a cable tie strapped on it to keep it from falling back through the hole and to protect it if it gets accidentally jerked.

I carried a folding dewalt screwdriver with a torque adjustment to avoid over tightening or breaking the  terminal. If you have 16 gauge and larger wire sometimes the terminal would allow the smaller pigtail wire to slip out. Try to get in the habit of putting it on the same side as the zone wire and crossing over or under it. Some of the controllers have a valve test terminal that makes the 24vac hookup easy but most will require you to determine which side of the 24 volt transformer wire to use. Try to find that out before you start wiring in the pigtail.

Wire strippers. Quality wire strippers are well worth the money. Greenlee makes a good line of tools and supports the irrigation industry. If you use them as frequently as I did then buying a new set every year helps. The remote connectors we sell do not require stripping. Each tip is scored to allow quick wire tip prep. Strip off all the tips that you know you will be installing and twist the wire tight before installing the pigtail. The strippers may be needed to connect the 24vac of the remote. I've used small trailer wire hookups as well. 

Keep blue and orange dry splices available. Many of the newer controllers unfortunately have gone to speaker wire style terminals. Some hold two wires well but some, the Weathermatic outdoor Smartline being an example, do not hold two wires well. I've used several methods depending on the circumstances. I've twisted the pigtail wire around the zone wire and pushed it back in. I've run a short wire from the terminal and wire nutted the three wires together. (terminal wire, zone wire, pigtail wire) I've used trailer hitch light connectors.

 If you are looking for the controller to carry that makes pigtail installs easy the the Rainbird modular is the easiest and fastest. The object is to get the pigtail installed in 10 minutes or less. If you get in the habit of installing them on each service call it becomes a much faster job. A return trip to a remote ready customer is worth the initial time and the customer is rewarded with much faster service calls in the future.