A good way to tell if a plant is getting the right amount of water is to look at the soil, not at the plant. Since water falls through soil to the bottom of the pot, soil that appears dry on the surface may be saturated underneath. It is a good idea to check the soil about 1 inch below the surface. When the soil is dry there, it is time to water again.

The type of water used can also have an effect on a plant. The fluoride in tap water as well as the salt in soft water can cause spotting and brown tips on leaves.

Light
A general rule of thumb is that the darker the leaf, the less light a plant needs. This is, however not true for all plants, in all situations.

One important tip regarding light is to know what kind of light you have in your home (lots of sunlight, partial sunlight, etc.) and buy a plant that thrives in that habitat.

Another important tip is to realize that plants can experience trauma when taken from one type of light to another. A plant that has been growing in a bright greenhouse will not thrive if placed in a dark shady spot, even if the care tag says that the plant likes shade. Gradually move the plant into the shady spot over time to reduce the chances of survival for the plant.

Windowsills may seem like the perfect place to have plants because of the amount of light, but it is important to remember that during cold winter months plants can easily freeze and during extremely hot summer months, there is a chance that plants will be scorched or sunburned. Keep this in mind, as it doesn't take very long for either of these effects to kill a plant.

Food
Plant food can be a great booster for growth, or it can have disastrous results, depending on how it is administered. Many people choose to steer clear of plant food for this reason, especially since most plants do fine without it.

If you do decide to feed your plants, make sure that you have chosen the proper food for your type of plant. Some plants need acidic treatments, others will wilt when given acidic food. Make sure you know what you are dealing with.

Giving a plant too much food is the second most common killer of plants. More food does not mean more growth, it means more concentrated minerals in the soil which the plant cannot digest and will eventually become poisoned by. Moderation is key.

Cleaning
Plants like to be clean too! Wash leaves weekly with a soft cloth and a mild solution of soap and water (one or two drops of soap in a bucket of water is plenty). Be gentle and wipe in the direction that the leaf is growing, with your hand under the leaf for support.

When tips of leaves become brown, it is perfectly harmless to trim them with a sharp scissors.

It is important to keep all dead leaves and other debris out of the plant, as they may cause decay.

Any dying leaves should be removed from the plant immediately (as soon as you notice them) because they say energy from the plant and can spread decay.