Getting to know your plant's leaves
Troubleshooting plant problems using the leaves is quite common, but can be a bit confusing at times, as leaves can show a variety of symptoms. It may even be that the symptoms are totally normal and are just an expected part of your plant's life cycle.
Therefore, getting to know what's typical for your plant is an important and useful way to identify potential plant problems before they develop into something more serious.
Check your plant's foliage on a regular basis, such as when you water
Gently remove any damaged leaves when you see them
How to spot a problem
Yellowing leaves and brown spots often set off alarm bells in plant owners, however, they may not always be cause for concern. Some plants are much more prone to discoloration than others, and a single yellow leaf on an otherwise healthy plant isn't going to do any harm - you can just remove it.
However, if the entire plant or large sections of it start to yellow and wither, it's most likely that there's something going on, such as incorrect watering or lighting conditions.
To state the obvious, plants grow over time! This means that a plant will start off small with fewer leaves and will eventually develop more as it becomes fuller / older.
It's important to remember, though, that the leaves themselves don't last forever, and so it's perfectly normal for your plant to shed older leaves, particularly its first leaves that aren't of any use anymore once it ages.