I'm an avid Ocarina of Time player. It's one of my comfort games, and it codifies many races and features that are mainstays of the series now. I'm also pretty hyped about Ship of Harkinian as well as other N64 decomps.
There are some in-game UI/UX hints that will help keep you spoiler free. I'll try to keep any spoilers vague.
- When you clear a dungeon or overworld area of gold skulltulas, an icon will appear next to the area name on the map. If it's not there, you have more to find.
- Annoyingly, for dungeons you must be inside the dungeon to see the icon.
- There is a reward for 20 Skulltulas that greatly helps finding secret holes in the overworld. You need a rumble-enabled controller to take advantage of it though.
- Write down where you collected a Heart Piece. There isn't a UI feature like the Skulltulas that hints at what you've collected.
- However, the maximum heart containers is 20, so you can calculate how many heart pieces you still need to find.
- Don't worry about full Heart Containers. They are only rewards for boss battles, just don't jump into the portal before picking it up.
- Somebody will ask child Link to play him an original song. The song can be (almost) anything you want but write it down. You will need it to 100% and the game never tells you what the song is again.
- You can change the song any time by playing him a new one as child Link.
- Personally I press the C buttons continuously clockwise as an easy to remember song.
Remembering your save location so you don't have to start back at your house every time
I use emulator save states because it's 2026, so no shame.
Some random things that come to mind. I keep it to advice, but spoiler'd just in case you want to be completely blind.
- Rupees fall from the sky, but your wallet is always too small. Spend freely.
- The Bean guy is a good money sink, and you will want to eventually buy him out.
- Do the Lon Lon Ranch side-quest early as adult Link as it will make early adult overworld traveling less tedious. This is less of an issue later in the game.
- Several side-quests have timers that have you schlepping across the overworld and you will be thankful you did this.
- It's not a bad idea to wait until you've beaten all the dungeons and have all of your equipment before going after the final collectables.
- There is equipment and songs you get during Adult Link that will make getting around and item hunting much easier.
- Even on my casual playthroughs I get all of the Gold Skulltula rewards minus the 100%. The 100% reward kinda breaks the game in a certain way too imo...