If you are reading this before starting the game, know that you are going to be in for a very long grind. This was my daily casual play game for a number of years so this for me came gradually. If you are just starting out (or still fairly new), I would reference the Top Shelf and Distinguished Service achievements to map out a long term strategy. If you are going to to stay free to play, this will only add to your grind.
First thing I would recommend (factoring a plan for Top Shelf) is to figure out which lines you are going to run. This is really more of a personal choice depending on how you play. I crushed at TDs, Arty, and Heavies. However I couldn't Light or Medium worth a damn. I'd also recommend reading online about all the tanks in the line. It is not uncommon to find a nasty surprise between tiers 6-8. What seemed like a great line suddenly is under armored or under gunned for the tier. Do the research because if you hit one of these "lemons" you will be hating life for that entire tier. Worse, sometimes the line doesn't recover and can be a very painful slog to tier 10. If you try to play them all, you will start coming into a silver crunch even with a premium account around tier 5-6. Therefore if completing this as fast as possible is your agenda, I'd recommend sticking to a line until Tier 10.
Best case scenario is starting with a ranked up crew from an event. This can save you at least one skill (if not more). The best ways to level a commander is to continue to use the same commander down the entire line. You will pay for retraining with either silver or gold. Keep that in mind when purchasing a new tank so you can afford to also move your crew. You will take an efficiency hit until they are trained up in the new vehicle. However the better crew you carry over will help your play in general.
Now specific to the achievement. 1. If you can afford a premium account, do it. If not and you get a hold of free premium days, play like a fiend on them to maximize their benefit. Pay attention to certain days which might grant a higher daily multiplier. 2. Premium tanks. If you manage to acquire a premium for the same country and type (either through event, gift, or purchase), rotate your crew to it at least once a day to take advantage of the daily multiplier and the natural bonus that comes with the premium tank. Don't overlook using your premiums. It doesn't cost to rotate a like crew to one and back. It is effectively getting an extra daily bonus multiplier to use with your crew. It adds up. I frequently used my premium crews in other vehicles to keep the premiums empty when not in use. It made crew transferring easier in my opinion. 3. Mentor skill. This is a must for the first skill. It grants you an XP bonus. Over the long term it can effectively grant "free" skills. However this is over the very long term. 4. Crew XP boosts. If you have them use them. They do no good sitting in your inventory. Keep an eye out for events offering them. 5. As you have the option, pick skills that will benefit your class of tank. While some skills seem one size fits all, consider how you play your vehicle. For example, if you are a TD, focus on things to improve your camo rating. A TD is a sniper. Maximize the opportunity to get in a devastating shot or two and then relocate. While camo might help a Heavy briefly at the start, once you are in the thick of it, there are better skills to have to keep you alive when you suddenly become everyone's favorite target.
Some general hints about maximizing your experience. This is a slower paced strategy game. Staying alive for as long as possible will pay off. Too many console players try to run and gun this game. Take the time to learn the mechanics. There are a ton of videos on YouTube covering the skills that will help you maximize your play. Learn to angle your armor. Learn how to use a bush properly to maximize your camo rating. Facehugging and side scraping can make you a stronger player in general. Learn about when to choose AP over HE. Learn the weak spots on tanks. I got accused of hacking more than once because I knew where to shoot a heavy even with a light. Crippling parts and crew can save your life. Make each shot count. Knowing how to ammo rack an enemy pays beyond belief. Also don't underestimate the XP gains from spotting and tracking vehicles. In general, play smart.