It is a good idea to narrow down the choices before you start browsing for floor tiles.
Firstly, you will need to determine what type of usage the floor tile is going to be put through. If the tiles are going to be for outdoor use then they will need to be able to resist the weather. If you live in the UK or another part of the world that has frosty conditions then you will need to ensure the floor tile you use does not absorb too much water. If a tile absorbs too much water then the tile can expand and become damaged when the water freezes. This type water resistant tile is known as vitreous or impervious. A vitreous tile absorbs less than 3% of its weight in water and an impervious tile less than half a percent. It is recommended that you use a porcelain floor tile for outdoor use simply because of their low water absorption. There are also some types of natural stone floor tiles that are also suitable for outdoor use and this includes slate.
If the area where you want to lay your floor tiles need to be non-slip you will need to choose floor tiles that have a rougher and less polished surface. You could also opt for a smaller floor tile such as mosaic which will lend themselves to extra grip due to the grout joints and tile edges. There are floor tiles that are specifically designed with extra non-slip properties such as dimple textures or by adding a textured substance into the glaze on the tile such as silicon carbide to create a non-slip surface, also you can have them as wood effect tiles.
You will also need to take into consideration the amount of wear and tear the floor will receive. An area of high wear will require a floor tile with a tougher glaze if you are using a non-porcelain ceramic tile. This will involve the tile is fired at a higher temperature for longer to give more durability. Porcelain floor tiles are suitable for high traffic areas as they are especially tough. If you are tiling in an area where people are going to be walking over it in shoes then you may wish to choose a darker floor grout which may also sway your choice of tile colour.
Keep your current colour scheme in mind when you are choosing your floor tiles. Keeping in mind which colours will match with your overall design will make the task of choosing floor tiles a lot easier. A larger format floor tile can be appealing in terms of the look but they will require a flatter floor. If the floor you wish to tile has a slope or undulation (more common outdoors) then you are better off choosing a smaller format tile which can follow the contours of the floor.