I can do kegels, and I try to do them regularly. But they stay weak. I'm looking to get some sort of toy/aid that I can keep inside me to remind me to do my kegels all the time. I've been browsing through the Ben Wa balls, vaginal balls and kegel toys, and (wonderfully, as always) there are just so many different options! I'm not complaining about the options; I just have no idea where to start.

Plus I'm one of those college students whose existence is supported by her parents. Parents who (wisely, I may add) haven't given me a credit card. Also, I just prefer cash. I suspect my mother would wonder should I magically get a credit card and start ordering stuff from "Web Merchants".
(last paragraph TL;DR: I don't have money to buy stuff)

So I would really like to narrow my options.

When you started on kegel toys, what worked better? Loose ball(s) or one of the toys with a string? A single or double (like the Teneo Uno or the Teneo Duo)? Or would something like the SinFive Emigi be better (since it doesn't have much of a gap between the two orbs)? What are your personal preferences?

I don't have a small vagina, so that's not an issue at all (if that makes any difference in the advice I'll get).

And as a general "Mari has no idea what she's doing" question, for double ball ones, do you insert only one in and clench around the middle, or do you insert both orbs?