Without using the loop you can make fortify alchemy equipment with a higher rating than 25% which would in turn help you make better potions without perks in your Alchemy, but that will also depend on the perks you have in enchanting. I think either way its gonna cost some perks for some better potions. You can also use up to four pieces of fortified alchemy equipment at once. Helmet/Circlet, Gloves/Bracers, Ring, and Necklace.
My favorite combination of ingredients for leveling purposes only is Blue Butterfly Wing, Blue Mountain Flower and Blisterwort. These three ingredients are very common and are easily found and when combined produce the effects of Damage Magicka Regen, Damage Stamina, Fortify Conjuration, and Restore Health all in one potion so each one made produces a good bump in your alchemy skill for some easy to locate ingredients. They also sell for some good coin.
Blue Mountain Flower, Glowing Mushrooms, and Nightshade also produces a pretty potent concoction. I sometimes prefer using this second recipe for leveling because the Blue Butterfly Wing is also one of the common ingredients for a fortify enchanting potion so I don't like to use too many up, but then again I can always walk outside and catch more butterflies.
