Making your user think as little as possible and save as much information as possible
In the case of selection of dates as an airline and hotel website, the user should start searching for a city and there should already be options, and if you select the date of entry, leave a possible departure date for the same month selected and year, preventing you from selecting each new search for a new exit date. On the Ibis website, the information is quickly populated and some fields are already enabled to facilitate the search.
This is very important in e-commerce in many situations; for example, when possible, save the last option that the user has accessed on your site. In the case of an e-commerce, if the user visits several products, let them have access to the last visited; this facilitates a lot at the time of purchase. In a few e-commerce websites, for example, you can see last products visited, even if they were on different days and still separated by categories.