Much of the literature you can find on time management involves turning yourself into some sort of robot. If you follow what you read, you’ll find yourself rising early, working through your lunch hour, staying extra hours late in the office, and/or deactivating your Facebook account.
While these are all techniques that can work, they are in my opinion, not low-hanging fruit. By working yourself to the bone every day, you can achieve maybe, a proportional increase in productivity. But that increase in productivity comes at a very real cost - your life. Startup burnout is a very real problem, and it is in my opinion, a very easy way to forfeit your hard-earned efforts toward building a company.