Beware: I am unable to write anything short or concise!
WK Levelling:
I don’t quite remember how long it took, but I was pretty close to the optimal speed of 7/8 days per level and half of that for the short ones… I could have remembered a few more kanji on the sorter levels and been done maybe a week or two earlier? Not of much consequence anyway.
Grammar
First I went through Tae Kim’s Guide to Japanese Grammar, drilling the sample sentences with Anki. That left me with a pretty solid foundation. I also studied the Core 6K/10K sample sentences.
Just recently, I’ve started watching the Japanese only content on the nihongo no mori youtube channel. I make flash cards with the sample sentences and japanese explanations, and am hoping this will work as well as Tae Kim did for the elementary grammar.
Non-WK vocab and kanji
Nowadays I just add all the words and kanji I look up to my anki deck and drill them that way. I make my own mnemonics for the kanji and add 10 a week. That seems to work pretty well.
I’m too impatient to drill complete sentences anymore, but just a few days ago I’ve started looking things up in j-j dictionaries as a first resort, so with luck, the answers themselves will slowly be replaced by sample sentences of sorts…
Reading
I started reading stuff as soon as I was able to. I started with the graded readers, then moved on to simple manga and video games. My current reading practice is making sure to read at least 2-4 pages in a real book each day (still plugging through the No 6 series i started last summer).
I recommend keeping a list (mental or otherwise) of stuff you want to read one day, and then check in once in a while (you can often read a few pages of manga/books on amazon or other book stores, and you can check games using let’s plays, called 実況プレイ（じっきょうプレイ）in Japanese).
Listening
Said 実況プレイ have always been something I’ve found to be a pretty relaxed way to get some listening practice in, since it was usually fun even when I didn’t understand anything at all! It’s also rewarding to go back to them later and notice that you can understand a bit more.
I’ve also written my own listening practice SRS web app.
Writing/Speaking
I’ve found two chat buddies using the hellotalk app, and write to them once in a while. I also have one hour spoken conversation practice each week using community tutors on italki.
Whew… I think that about covers it!