1. Before attempting the earn all the achievements, make sure to play through both sides of the campaign first (the Triple Alliance and Triple Entente) and earn three stars in each mission. Then, spend the stars in the Skill book to unlock different types of perks.

2. I highly recommend, that you unlock all Dogfight perks, Ace perks (except the last row, where you should only unlock the Squadron III and Final Takedown III perks) as well as mission perks (the first two rows).
-NOTE: If you completed the campaign in single player mode (like i did) and didn't complete a few missions in Co-op mode after it, you won't be able to unlock all perks in the skill book.

3. Choose a plane that is fast and highly maneouverable (like the Nieuport 17, Albatros D5, Junkers J7 or the Airco DH2).

5. During the mission, try to keep the Combo chain going until the end, you'll also need to complete the mission in the shortest time possible.

TIP: To keep an enemy plane in your sights, you need to adjust your speed according to the circumstances
(low speed for evasive enemies and high speed for out-of-range enemies).

Good luck and good hunting !