1. Life is a marathon..
You have to realise that whatever choices you make today, they will affect your long term in some way.
So you always need to have a long term perspective.

2. Its not about how many projects you executed..
What matters is the number of projects you executed well.
So, you might pick up a single project at a time - but make sure you execute it well.
No point in picking up multiple projects at once.

3. Think Macro and also execute micro..
Have the ability to think at a macro level - look at the bigger picture and take decisions that will lead to long term gains.
But at the same time, have the ability to execute at the micro level.
Develop the ability to do both simultaneously.