Some of my ideas (that would certainly contradict other people's) :
- Make difficulty ramp up slowly but surely.
- Only normal boomerang, and stun is enough. Magic Rod could hurt and stun at the same time.
- If burning trees is key to finding secrets that are important, then only have Red Candle, found earlier.
- Make 2-3 dungeons accessible by normal means, and others more hidden, requiring items to reach, and with reasonable hints.
- My opinion on good hinting for dungeon location is: one general hint, easy to find, and one more precise hint that you find using an essential item.
- Don't hide the first sword far away from the beginning. Hacks that abuse this are awful.
I can help with ASM.