Another thing to inspect is how well lubricated your chain is. If you've ridden in the rain, a post-ride clean will get rid of any dirt and gives you a chance to dry your bike. This will stop it from rusting.
Even in dry weather, you should regularly lubricate your chain to make it last longer. A fine layer of oil is enough to keep it running smoothly. But don't apply too much! Once you've lubricated your entire chain, turn the pedals and wipe off any excess oil with a cloth.
Avoid grease at all costs. Your drivetrain will be lovely and quiet, but grease has the big disadvantage of holding on to dust and sand. When covered in this mixture, your chain will be very abrasive, which will severely shorten the lifespan of your sprockets and chainrings.
If you want to be certain of your chain's state of health, it's worth "investing" €10 in a chain wear indicator, which will easily show you how worn your chain is. It means you won't end up changing your chain too early or too late (causing increased wear on the chainrings and sprockets).