I'm a disorganized person, too, extremely so; but I was afraid of spinning my wheels in the mud when I started learning, so what I do is adhere to a few rules that I actually kind of stole from a personal trainer I know:
1. (Obvious, but I): Do something everyday with the Russian language, even if the activity is inane, or seems like too little work to be study. (Ex: on lazy days where I don't want to work after work, and I just play video games - well I've modded most of them to show russian text. Ex2: I often can't stand to do any more studying (russian && science journals and things most would find dorky) I will free-write something fictional and childish to push the blood back into my right brain... =) Well, I have a steno pad, I write these things paragraph at a time, then translate what I wrote on the right column. (Usually the translation is laughable: I use words I've not seen before in Russian, but still I learn, and friends who speak Russian help me find errors and re-draft, and thus indirectly pump up my vocab.)
2. I seek out my weak spot everyday, like I would in a workout routine. I try to find the arena of the language I've not worked on, or one I'm struggling at, and I focus my day on that. Ex: when I found I had a poor understanding of <сам> and its 28 incarnations, I made flash cards (decl/meaning) and read them forward/backward throughout the day. Ex2: When I realized my aural cognition was poor, I D/L'd recordings of Russian news articles read at fast speed, and their respective transcripts, and listened to them one at a time, trying to mouth the sounds along with the speaker until I could keep up, and until my ears could tell where we were on the paper.
3. I attack myself (my ignorance?) from all angles. It's not uncommon for me to spend a morning listening to Russian talk radio in my headphones while I translate a paragraph of Russian and intermittently watch a sharedtalk chat room for living language examples.. When I've got enough material coming at me from all sides, it seems that my innate ability to ignore or tune out the unfamiliar fails, and the Russian language just pours in. Also, the more I minimize English I hear, and maximize RUS I hear in a day, the better I take to it when I sit down to study. NB: In response to Marcus' statement, here's where I find myself using textbooks, onlines resources and books on tape, and I agree it's harder to learn without their help. (I suppose it's *possible* to learn without a lexicon - but I like to know the rules of the game, so I"m more comfortable with one.)
4. I challenge, but never test, myself. Good or bad thing? I don't know; but it's important to me to keep the whole process fun. So I never frankly test myself; instead I try to see how I'm doing through interaction. I write a note on masterrussian.com, and if I speak RUS and nobody corrects me, I pat myself on the back. =) Or I'll try voice chat, or watching a movie or TV show in russian and check myself for comprehension afterwards.. This way I'm never discouraged by failure, but I can still check my level of skill, and keep the whole thing fun, as a hobby should be.
5. I change it up whenever there's an opportunity. If I've been doing something for awhile, and it doesn't feel new and interesting, I switch it up, try to find a different approach. Too many chat rooms - I switch to the books; too many news articles - I listen to talk radio or even russian dance radio or folk music.. Whatever incarnation refreshes my love for the language. That's what the motivator is for me.
I'm interested to hear how people study when they're more organized than I am. =)