Completing the areas that your personal story has sent you through will guarantee quick level progression. You have to make sure that you continue to gather resources and complete dynamic events. This will be the slowest method when being compared with Edge of the Mists and Structured PvP. But it will give you a lot of resources and GW2 Gold for your character.
Participating in PvP
Tomes of Knowledge provide an instant level up and can be obtained by ranking up your Reward Track in PvP. This is recommended for a player who is familiar with the mechanics and meta-game of Guild Wars 2. Writs of Experience provide 5% of the needed experience to reach your next level. You can trade 20 Writs of Experience for a single Tome of Knowledge at a Mystic Forge vendor.
More Information please check:https://www.mmogah.com/news/guild-wars-2/guild-wars-2-guide-how-to-level-up-fast