It's sometimes easier to think of what will make you fail at something than what will make you succeed. That's why I like the technique of "inversion" - instead of trying to be successful, just avoid the things that cause failure and you will succeed. I also like the practice of doing "pre-mortems" before starting on any project or team - imagine you failed, think of all the reasons why, and then prioritize and mitigate them.
Here are some common failure modes that you can try to avoid when you are pursuing anything - personal, career, business, relationships, etc.
1. No burning curiosity, desire, intent, or conviction. Most hard-to-achieve things take a long time and a ton of effort. So if aren't really emotionally, rationally, and intellectually drawn to a pursuit or excited about the process, just pursue something else you actually are drawn to. Seriously, why pursue things you don't want or need?!
2. Lack of deep understanding (and failure to keep learning) of the problem, solutions, and space. You don't have to know everything when you get started. But learning and research is a good place to start. And continue to have a beginner's mind and never stop learning. A good mentor or coach can accelerate your understanding quicker than most books or courses.
3. Misguided (or missing) strategy or principles. Goal without a strategy or a plan is just a wish. You should have a strategy that includes clear goals, levers to achieve the goal, current position, strengths, weaknesses, threats, etc.
4. Poor planning. Without comprehensive, specific, and actionable plans, strategy is just a theoretical and intellectual exercise. Plans should identify specific whats and hows - metrics, requirements, processes, milestones, resources needed, owners, and timelines.
5. Poor execution. This could happen because of a whole bunch of reasons. Not having the right level of skills, standards, effort, or attitude, not being consistent, not working well with a team or having a wrong team, not paying attention to details, doing too many things, etc.
6. No regular objective retrospectives, feedback loop, or measurement. This is probably the most important one. It's easy to be in the weeds and lose the bigger context, or to fool yourself. If you do this one thing well, you can catch everything else.
7. Not course correcting. As they say, the definition of insanity is doing the same thing and expecting something different. If things aren't going well or improving, change. Even better if you can change before things get bad.
8. Getting complacent. It's very easy to get to business-as-usual mode, rest on laurels, or become cocky. Keep learning, keep innovating, and keep getting better.
9. Not getting help. Seek advice, help, and partnerships from others who are able and share similar desires and values.
10. Being greedy. If you are not sharing the success or caring for others, then you aren't going to be supported for long or feel that good or motivated either.