Stack Packs
The biggest thing that you can do, though, is start stacking packs.
People do stack packs because they don't really like the promos available that we have throughout December and the beginning of January. They would much rather have a Team EA FC 24 Coins of the Year because these end up being the highest rated FC 24 Players within the game. Depending on who you get, which is typically defenders, midfielders, and attackers (not a goalkeeper), they will probably be valued at 800,000+ coins.
With your midfielders and attackers, it's likely 1.5 million +, going even higher than that, six to seven million, dependent on the player, such as Mbappe, for example.
Even though you have a much higher chance of being able to pack good players as part of promos throughout December and beginning of January compared to you being able to get one of these Team of the Year players during the Team of the Year promo, people still like to test their luck.
Game Modes
The best way to do this is to stack packs. That means going through Game Modes, through Division Rivals, getting at least 3 wins to qualify for a reward.
Then, aiming for 7 wins to max out that weekly reward. You'll need 1,250 qualification points to enter the Champions playoffs, claiming packs from there. Aim to get into the Champions finals to claim additional packs.
Afterward, go into Squad Battles to achieve as high a rank as possible. Use your coins, draft tokens, or even FC Points to play through drafts, whether single-player or online. Additionally, engage in Moments to build up as many stars as possible. By the time Team of the Year arrives, spend those stars on packs.
Objectives
Everything mentioned ties into objectives. You may want to FC Coins go through challenges that require you to play through friendlies.
Objectives end up being the best way to grind packs because of your seasonal progress and the content EA releases. Stacking these challenges up ensures you're obtaining packs from objectives itself while competing within the mentioned game modes.