For our espresso, we recommend using a good quality filter basket (commercially sized examples being IMS or VST), we generally like to start with the basket's stated dose size.
We've found delicious results at 93°C running a brew ratio of 2.5:1. For example, with a 20g VST basket, we might make an espresso that weighs 50g.
For this style of espresso, contact times are usually between 28 and 32 seconds depending on age, and if your machine allows for preinfusion, usually 5-6 seconds. For coffee that is fresher after roasting, you might be on the shorter end of those contact times, or perhaps slightly longer contact times for coffee that is a little older after roasting.