Time management might be the most important thing for solo indie. Because you work alone, your time is very limited.
I think there are 5 things you need to consider so that you can make a good game.
The pecentage is the approximate time I spent on these categories
* Game design (40%)
As the most important part, It took 40% of the time. It's the soul of game dev.
You need to make you game unique and able to stand out of thousands of other game. you can copy other game idea, but it’s not your game.
Game design doesn't work like this:
game design -> make the gameActually it works like this:
game design -> make something -> game design -> make something (Loop)
* Coding (30%)
Personally, I like coding but I have to work efficiently.
- When run into problems, Google first.
- Make good use of unity asset store, such as localization, mobile native plugin.
- Keep version control. Unity collaborate is a good tool to backup you project.
* Art work( 15%)
I'm not an artist, but I do learned how to use PS and AI.
- I bought asset from others and amend it to fix your game.
- Otherwise I used simple geometry and proper color in the game, just like my game SpiderBall.
* Sound (10%)
It worth your time to do a little sound design
- Buy sound track as background music (Asset Store),
- Made sound effect (Bfxr),
3' Put them together in a sound process tool like Ableton
* Marketing (5%)
- Facebook page, post the news about the game, help to track record of your game
- Post the game on toucharcade, indie game dev group.