Experts can be added to your list in one of two ways:
1. Hiring experts immediately and automatically adds them to your 'My Experts' list. It doesn't matter whether you contacted the expert directly or via PrestoExperts's posted requests.
2. You can choose to add experts to your 'Favorites' list after a session with an expert (on the rating page), or by going to the expert's profile on the website and clicking the 'Add to Favorites' link.
Also note that you may also filter your expert list by your desired criteria using the 'Sort By' button on the right hand side of the list.