Practice, Practice, Practice (informal survey and general discussion)

I never practice. The more time I spend between playing, the better the play. Once you learn, you don't practice, you play. I don't even have to do that much either.

I find this to be true.  Sometimes when life is busy I will go several weeks without playing and it seems that playing is more effortless and sounds better.

Hi everyone! I've been an occasional visitor to these forums since starting the theremin in 2017. Decided to join the conversation today :-) 
I am a human computer interaction researcher and a big learning nerd. Started the theremin as an experiment in learning. Been documenting my progress with little video clips on Instagram for the past 4 years (https://www.instagram.com/_xiaosquared_/). Glad to see discussions about how people practice here! 

To answer your questions: 

1. Do you keep track of your practice time?  Is it informal, or do you write it down somewhere? 
I try to do at least 30 minutes a day on theremin, but I don't keep track of it formally. I also play piano for around 30 minutes every day and do singing warmups in the morning and evening. On piano, I am slowly teaching myself the language of harmony and try to understand the harmony in the piano parts of my theremin repertoire. Songs I play on theremin are too difficult for my current vocal level (just a beginner), but I still try them to better understanding phrasing and breathing. 

2. How much do you practice: like 15 minutes, 1/2 hour, or an hour or more per day? 
On average between 1/2 hour to an hour. If you count all my musical activities, it's around 2 hours per day. 

3. How you keep track of your repertoire? 
Dropbox folder with sheet music, accompaniments, references

4. How often do you attempt a new song? 
It varies. 6 months into starting, when I was first able to play more or less in tune, I was trying something new every couple of days. Now I'm trying to polish my playing more, so I am just starting a new scheme. Currently working on a bigger classical piece until I get it to a high level of polish, which might take a couple of months. Also starting to work on some jazz standards on the side. I'm expecting to try new ones of these every couple of weeks or so.