Tea ball
Tea balls come in different shapes and sizes and are easy to find and use. But even the biggest ones are relatively small and limit the taste of the tea.
For the tea to get its taste the water needs to get in contact with the leaves and the leaves need to unfold. But inside a tea ball the tea is trapped and the water only reaches the outer part of the leaves. This results in a weaker taste and wasted tea on the inside that never got brewed.
A tea ball should be used with small leaf grades and only be filled half-ways.
Tea bag
Empty tea bags usually come in small, medium and large sizes.
These bags are more environmentally friendly than regular tea bags. They are usually made of recycled paper and contain no plastic contrary to most prefilled tea bags, which often contain plastic.
The bigger sized bags are good for brewing large leaf teas or brewing in a big pot. Smaller sizes are used directly in the cup or mug.
Mesh infuser
Mesh infuser are similar to empty tea bags and can be washed and used multiple times. They have a good amount of space for the tea to float around and can be used for multiple steeps.
When used a lot, especially with black tea, it will get stains and discolored.
A mesh infuser with a lid on top prevents a lot of aroma escaping and it can be used to put on the infuser between brews. Mesh infusers are best when used directly in the cup.

Tea pot with infuser or strainer
There are tea pots with built-in infusers or strainers. Some have a strainer built-into the spout and will keep the leaves in the pot while pouring. Other have a built-in infuser that can be removed.
Tea pot with coiled spout filter
Tea pots can also be equipped with a coiled spout filter. This is more common on glass tea pots and also comes in different sizes, from 150-1200 ml. The coiled wire in the spout stops the leaves when pouring and keeps them in the pot.

French press
A french press is used for coffee more often but can be used for tea as well. The leaves are put directly into the container and can be used for multiple brews. The container is easy to clean.