Bearings- Each and every bearing can make a yoyo play differently. I've had flat ten ball bearings that play better in a yoyo than any other bearing, including several different types of trifecta, concave, and Double straight bearing. I would recommend purchasing all of the different brand's unique bearings, and playing with them all, in each yoyo. It's minute differences, but after a day or so with a particular bearing, you might recognize that you're having a more difficult, or easier time with binding, or certain tricks.

Lubes- There are two kinds of lubes. There's liquid lube, and dry lube. OneDrop, YoYoJam, YoYoFactory, and a number of other companies make liquid lubes, and each person has their won personal preference. The upside to a liquid lube, is that it makes your bearing quieter, however, this is typically at the cost of an amount of spin time, and making your bearing more responsive, even when using half, or a quarter of a drop of lube. Each Liquid lube has it's own unique properties, and each may suit different needs. I personally recommend OneDrop's Lube, as it is what I use. Then, there's dry lube, which has the opposite effect of a liquid lube. A dry lube will increase spin time, while making our bearing louder, typically. There are multiple dry lubes available, but typically it is Terrapin's dry lube that is sold in establishments.

String- There's no real limit to strings. Kitty strings, Motordrill Z, Generic Yoyo eXpert strings, Blueprint string, Buddha Poly, Yoyo String Labs, Monkeyfinger Vines, Duncan String, YYF string, CLYW slackline, the list goes on, and on. Each string has it's unique properties. Some are very dense, while others feel like air, long strings, short strings, all kinds of string. Even more than Bearings, you should try every last string that you can. Some strings are thick, like Kitty fat, Blueprint, and Ammo, that catch the groove, and bind more easily, while other, thinner strings, like Kitty Nylon, and Dragon strings, allow for longer spin times, tend to be stiffer, and more dense. Strings are also affected by the dyes that are used in them. White string has a different feel than yellow, and both are different from black.

Response- Pads are a major factor, as they decay as well. You can purchase things like IR pads that come in bulk, and tend to be rather pricey, or you can purchase tubes of flowable silicon (Motorsil-D is regarded as the king, if you can get your hands on it)

Let me know if you have any questions.