>>270419711. Give nicknames, although this should be standard.
2. Don't underestimate ANYTHING. I've lost too many pokés to being distracted fighting against random trainers and them managing to pull a counter or some shit out of their ass, which leads me to;
3. BE WARY OF MOVES LIKE COUNTER, MIRROR COAT, DESTINY BOND, ETC. SERIOUSLY. This also makes Wobbufett one of the biggest threats in a nuzlocke, so have a poké that can evade shadow tag up when going in an area with wild Wobbus.
4. Always account for crits. Losing a poké because of a random crit sucks a lot.
Can't really think of any more right now and i believe you already know the rules.
Never give up, never forget, grind like hell.