Pretty much, although there are various ways of doing this.
Read a chapter and underline each unknown or doubtful word in pencil.
At the end of the chapter, go through with a dictionary(footnote 1), look them up and write them into a notebook(footnote 2). For nouns, write singular & plural but only write the gender if it’s feminine (since most are masculine). For verbs write down the dictionary head-word form (which is not an infinitive in Welsh), and if the dictionary gives it, the verb stem.
Same as above, but write the words onto a card. I buy A4 card and cut it into 4. Each piece will fit into most books, and I use both as bookmark, and to write down the words. At the end of the chapter when you look up the words you can write the meaning on to the card, and eventually all the words into a permanent notebook, or you can just write words and meaning straight into a notebook.
Dictionary: I almost always use an electronic dictionary these days. There are several good ones, including GPC and the one produced by Bangor University (PC and mobile versions).
Notebook: Some people prefer to record their “new” words electronically in a computer or phone app. I prefer to write them by hand, as I think there is a value in doing this.
I also absolutely do not use any of the programmes or apps for learning or revising words. They work for some people, but they are not for me. In fact, I make no effort to “learn” words whatsoever. I rely on the power of natural repetition and recognition. I feel this is in the spirit of SSiW.
Now there is a “system” of helping to consolidate vocabulary which is based on handwritten material. I have used it, although not as much as I intended to, and I’m not currently using it. I may go back to it when I can get myself organised (ho ho ). It’s called “The Goldlist Method”. You can probably find references to it in this forum if you search, or it can be found quite easily by googling as well. However, I think you can do almost as well just writing them down plainly in a notebook. Just use a reasonable quality, hard-backed notebook, and write as neatly as possible. Those are two principles I’ve borrowed from “Goldlist” which are worth carrying over into any manual method based on handwriting.
I’m currently using A5 hardback notebooks. A6 notebooks are too small, and A4 can be a bit unmanageable (although it (or bigger) is recommended by the Goldlist inventor).
Congratulations on getting through all 3 courses and all 3 levels by the way. I’m sure you’ll go far with Welsh, and as ever, “pob lwc”!
I absolutely think that after getting the basic structures down, which SSiW does for us so well, then the absolutely key thing in language is vocabulary, vocabulary, vocabulary. (And I wish mine was bigger). As you probably know, your passive vocabulary is probably always going to be a lot bigger than your active vocabulary, and probably after a few more years, you will be absolutely amazed at the number of words you recognise and know passively, even if you wouldn’t necessarily bring them into a conversation.
Oh, as well as meetups, don’t forget about online conversations, e.g. Skype. these can be extremely valuable.
And on books, don’t be too unambitious. Learner books are great, and I love them, but don’t be afraid to stretch yourself sometimes.
Oh yes: Check out the Parallel Cymru thread!!!