Yeah I've done quality in this game, it's very Ash of War/whetblade focused because you'll be swapping between str/dex scaling physical and elemental infusions, plus quality as an infusion is only great after ~45/45 so its mostly infusing strength weapons with heavy and dex with keen... It's just more efficient picking strength or dex and pumping it to 80 since most weapon catagories have at least one weapon for each.
I'd personally recommend you should try going with that Demon's Souls greatshield build, but instead infuse the weapons heavy to double down on the strength needed for the shields. It also gives you an out by letting you use other strength weapons two handed so you reach peak scaling faster if the shield doesn't feel to good to use in certain fights. They don't have to be slow weapons either, hammers (and especially the mace with its R2) are perfectly reasonable strength weapons with their posture damage and infusion ensure daggers still deal good reposte damage. Hell, guard counters let you use most weapons from behind a greatshield so don't just look at (heavy)thrusting swords/(great)spears if you wanna use one, just don't try to force it if you can't find an opening.
If you wanna do an int build, pure int pivot into int/fth was my first build and honestly only using Pebble/Rock Sling made me feel ashamed. It's better than it used to be as the spells were patched to be more fp efficient. Just don't use Crystal Burst/Crystal Barrage or death sorceries (except Ancient Death Rancor), they're not worth it. Otherwise just use spells that you find and see if you like them. Magebane Ruins in Weeping has a spell you can use on horseback and around corners, if you splash faith magma sorceries can be found in Mt. Gelmir (among other things) and there's a cave around the bottom of Raya Lucaria away from the enterance with stuff that mages really want to get. Obviously Raya Lucaria and Selia, Town of Sorcery are important for mages with lots of spells and talismans inside, as well as places with Alabastar/Onyx Lords (large naked men with swords) or Also the claymen in the underground area drop an infusable int scaling spear. It's good with magic/cold and poking with it makes imps a nonissue, even with a basic medium shield, plus you can get it right at the start, along iwth Gravitas ash in Limgrave south of Lake Agheel, just find the spirit spring off the southern ledge near the First Step grace. Night sorceries aren't dodged by enemies when cast so use those or the glintstone star family of spells if that's giving you trouble. Finally, remember that some spells can be chain cast between each other and charged, something I noticed players neglect so consider this a reminder.
A few general tips in no specific order; jumping makes your character's bottom half not have a hitbox, please use this. Some people don't really use it but it's the game's vertical roll which lets you have two different speed/damage rolling attacks AND lets you cover horizontal ground when preforming, it takes getting used to but made some bosses much easier. Level vigor early and often, aim for 40/60 when casting/melee respectively unless you know what you're doing or are a dumbass who wants 70/35 int/fth like I did. Splash some points into faith, as said above. There are spells that give you extra single elemental reduction and cleanse poison AND rot if you get 10 faith. All characters can wear a talisman that boosts it by 5 points to use them without levelling faith, but for that there's a spell that boosts physical/fire damage at 15 faith, which is more of a boss buff while the others are more for exploring, so getting 10 faith reduces the need to constantly swap talismans while roaming with the defensive buffs. You also can't stack every buff, the slots are weapon, aura, body, and unique buffs that don't follow the rule, all of those seperately can stack. Light roll doesn't increase i-frames, but it GREATLY increases roll distance, even after nerfs it's legitimately worth going naked if you know you can dodge the enemy, so don't sleep on lighter armor. Also for some reason if you see an enemy use gravity or a dragon, use gravity or certain dragon weapons on it if you have any you're using them at all, you get like 20 or 30% bonus damage if you do.
