First relax and don’t get frustrated, don’t treat it like work but more as a game, Scrying is not something anyone should be straining over.
Next you’ll want to get in the habit of doing it at or around the same time everyday, Again don’t see it as something your forced to do but as a fun activity you enjoy doing, i can’t stress that point enough.
Now i recommend working with Mepsitahl if you have not done so already, She’s one of the best to help with develop abilities like clairvoyance, and spirit communication. And fortify it many times over.
But whichever Spirit you choose, gaze at the sigil (it may help to hold your right hand just over the mirror when you do this, to let both you and the spirit know that’s where you want it to show up) when you feel ready say out loud for the spirit to show itself to you, then gaze in the same relaxed way you use with the sigil and let whatever comes come, don’t try to force anything just receive what does.
Scrying is in the mind, the magick imagination, the mirror and sigils are just tools, so don’t dismiss what’s in your head for the expectation of seeing things with your eyes, i had a lot of trouble in the beginning, an image would pop into my mind and i’d kept ignoring it because i was so intent on seeing with my eyes, until after a few weeks i realized there was no differences between those two concepts, once i understood that things really took off for me.
It will help you a lot to say again out loud what your seeing even if your alone “See it, Say it” and always try to keep a written record of your scrying sessions, that also helps out a lot in the long run.
And lastly once your done with a session give yourself a few moments to adjust back to normal reality (so you don’t walk face first into a wall instead of out the door. And yes that happen, more then once ) In fact If your anything like me once you get heavy into Scrying grounding becomes the hardest part.
Hope this helps you some.