Storage is important to homemade products. All my products will have expiration dates on them. If precautions are not taken, the shelf life of your products could be diminished.
The best place to keep your products would be in a cool dark place, or at least a dark place.
For example, my lip balms. I alter the product just a little bit with the amount of beeswax I use for winter months vs summer months. Lets be honest, we ALL have lip balm sitting in our cars! I know I have one sitting in my cup holder right now. :) Products, such as your lip balms sitting in the hot sun can cause them to expire quicker.
So what do you need to look out for? Smell them. Smell will be the first indicator that your product is bad or going bad. If it is a lip balm, taste would be the next indicator of a product going bad. The next thing to look for is application of the product. An example would be, if you are having a reaction to the product, where you didn't have in the past.
The good news is, if you store your products properly, you may find they will be good past my suggested expiration date. So keep in mind the smell, taste (for lip care), and application when you are getting close to the expiration date I had written on the product.