Training doesn't need to be complicated. Most progress comes from doing a few basics really well, and avoiding the mistakes that slow you down. Rather it be gym, running, or triathlon – these are the simple do's and don'ts that apply to almost any sport.
Keep it consistent
Start lighter than you think
Focus on form first
Have a plan
Build recovery into plan
Track small wins
Go "all in" too soon
Skip warm-ups
Compare your progress to others
Change plan too often