Prioritize Longevity

Be wary of techniques and scenarios that have a high chance of self-injury.

Longevity is key to a successful Jiu-Jitsu journey.  The best way to ensure longevity is to avoid situations with high risk of self-injury.

Some techniques, even when done correctly, can take a toll on your body.  These are often techniques that rely on high impact or unnatural twisting of your joints.

Exactly which techniques impact longevity may vary from person to person.  It's important to be aware of your body and understand which techniques don't feel natural.  For myself, it's double leg takedowns and truck entries.  I know that my body doesn't respond well to these techniques, so I avoid them in favor of ones that work better with my body type.

Also, be aware that many injuries occur during scrambles or uncontrolled flurries of motion.  This is because these situations occur when you don't fully understand the position you're in, and you're trying to compensate by using athleticism.

When you don't fully understand your current position, it's hard to keep awareness of where your limbs are and whether they're being bent in unnatural angles.  When you add explosive motion on top of this, the chances of injury are high.

Lack of positional awareness + compensating with explosiveness = high chance of injury.