The most important thing to do is to look around your home for any obvious concerns. Anything that is a quick and affordable fix might be worth addressing. You should also make the inspector aware of any improvements you have made, like new windows or granite countertops.
You can also look at the comparable homes sold recently to see if there is anything your home is lacking that might affect the value. People often ask if they need to clean their home before an appraisal; while it won’t make a significant difference, it can’t hurt.