How to Determine Your Team Composition
When playing Teamfight Tactics, you need to find a specific direction to build your team composition to maximize the strengths of your champions. Otherwise, you might find yourself feeling “lost” in the mid-game without knowing how to build your team. One of the simplest ways to determine your composition is to base it on the attack items you currently possess.

If you have Wooden Bows, you might consider compositions revolving around Kayle, Zed, or a brawler team with Shyvana as the carry. In case you acquire several B.F. Sword, compositions like Olaf – Butcher or Talon – Enlightenment are the most suitable choices. With a Tear of the Goddess, a composition centered around Veigar as the carry is optimal in the mid-game. If you possess many Giant’s Rods, you should aim for a team using Aurelion Sol as the main carry.

In cases where players receive too many defensive items and lack a clear direction, what you need to do is grab offensive items during the general selection round.
Adjust Your Playstyle According to the Game Situation
Observing your opponents is one of the most crucial skills in Teamfight Tactics as it provides you with information about them. This skill becomes even more important in the current meta of hyper-rolling and fiercely competing over units. The advice from the experts is that when observing in the mid-game, if 2-3 other players are also using the same hyper-roll composition as you, the best course of action is to abandon this playstyle.

However, you don’t necessarily have to sell off all your current units to immediately switch playstyles. Players can use their existing 2-star units as places to hold items for future carries. For example, when abandoning the hyper-roll Nidalee composition, you can still use this unit to hold items like Hextech Gunblade, Guardian Angel, or Infinity Edge… By the time you find stronger carries like Aurelion Sol, Kayle, or Olaf, it won’t be too late to sell Nidalee.
Focus on the Main Carry in the Mid-Game
The main carry in the mid-game will be the strongest unit you possess, typically a 2-star champion with many items. If you want to secure victory in this phase, maximizing the power of your main carry is extremely important. For example, with the following composition:

We have a 2-star Garen with 2 Iron Solari Chains and activated 3 Vanguard. In the bench are Aatrox and Braum, 2 Vanguard units. Many players will choose to keep the 3 Vanguard and Nidalee on the field, thinking this will allow their team to deal more damage. However, the correct play here is to remove Jax and Nidalee to add the 2 Vanguard units from the bench.
The reason is that your main carry is Garen; activating the 4 Vanguard bonus will make this unit incredibly tanky and give it the chance to deal significant damage with its Judgment ability. Furthermore, the 2 Iron Solari Chains will maximize their effect when there are more melee units.

Playing this way will help you win much more easily in the mid-game by fully utilizing the power of your current carry. In the event that your Nidalee has also leveled up to 2 stars and has items, it might be a better choice to drop Jax and add a Marksman unit instead.