The most powerful habit you can adopt: Using the first hour of your day to build, write, or produce something of value. - Dan Koe

You don't need to focus harder. Focus is the byproduct of a lack of distractions. You simply need to be in the right environment (mentally and physically) and have a clear set of tasks that you have the knowledge and skill to execute. Ignore everything but that.

Front-load your decision-making.

Write, build, lift, read, or do whatever your lever-moving tasks are first thing in the morning.

Because I can almost guarantee you won't have the energy, clarity, or discipline to do them (well) at night.

Most people quit because they forget that you have to be bad at something before you can be good at it. It's so obvious. You suck. Of course you're not going to win in 2 weeks. But if you can learn to enjoy extended periods of failure, you will make it very, very far in life.