I've played Final Fantasy X countless times. I can quote characters, I know the locations of all the Al Bhed Primers and other important items, and I know how to make my characters what I want them to be. With Final Fantasy X HD Remaster out now, many people are playing Final Fantasy X for the first time. Here are five tips to make your games easier:
1) During easy battles, even if you don't need to, take the time to switch Yuna in and heal one or two of your other characters. A lot of people assume Yuna is only good for summons. It makes sense, as her official title is Summoner, but she eventually becomes a kick-ass White Mage with some very powerful abilities. Having Yuna summon for every battle will neglect the growth of your other characters, and using Yuna only as a Summoner neglects Yuna's growth, because you won't always need to summon. Switching her in to heal is easy and fast, and will let her earn Ability Points with the other characters so that you can develop her faster on the Sphere Grid. The quicker she becomes that kick-ass White Mage, the better, right?
2) I plan to write an article on the best way to use Tidus, but I want to go ahead and say this: manipulate Haste! In my opinion, Tidus works best as a Time Mage. I have him attack swift foes, and when he has nothing else to do I have him attack other enemies, but he has access to some great support abilities like Cheer and Haste, and those should not be neglected, particularly in boss battles. Cast Haste on Lulu, and have her exploit boss's weaknesses with Black Magic. Cast Haste on Tidus and have him ready to heal, attack, or support your party in whichever way you need him. Pay attention to his Overdrive Gauge, and use Haste to get Tidus to Overdrive quickly and often. This brings me to...
3) Overdrives are awesome! Find out how your characters fill up their Overdrive Gauges, and get them to Overdrive often! Later on in the game, you'll be able to set how your characters fill up their Gauges. Pay attention to how you use your characters to choose the best option possible.
4) Pay attention to which Spheres enemies drop, and if you find an area where Ability Spheres are dropped, fights battles and stock up! Ability Spheres are hard to come by toward the middle of the game, and you don't want your characters stuck on the Sphere Grid or having to pass valuable abilities, causing you to waste AP to go back and get them.
5) Utilize Kimahri. Many players avoid using Kimahri, and I don't understand why. Kimahri has a very convenient starting position on both Sphere Grids, which makes him very versatile. You can make Kimahri anything you want him to be. Want another Black Mage? Want another healer? Want a destructive warrior? Decide how you want to use Kimahri early, and take him in the appropriate direction on your Sphere Grid. I personally send him down Tidus's way to get speed, and then mid-way through, I move him to Auron's area to get power. Kimahri ends up wrecking face and taking names. That's just in my game, though, and I realize everyone plays differently. Decide what's best for you, but definitely take advantage of Kimahri. He's a wasted opportunity otherwise.