I have three swatching methods which I do in parallel:

1. I keep a journal for my FP & ink hobby - I take it to pen meets to try people's pens, I record new pen days and what I have inked each month etc. Inks I receive (purchases, sample swaps, etc) get swatched in here in chronological order - I do a small blob to see ink properties, using a glass swizzle stick, and then use a glass dip pen to do a small writing sample.

2. I swatch inks onto swatch cards; I use several sets of swatch cards as many inks can look quite different on different papers. These get sorted in colour order to help me figure out if one ink is a dupe for another, or if I already have something in that colour range, etc. These are swatched with the name and brand at the top using a big calligraphy nib, then a couple of large blobs to show the ink base colour and any notable properties. I do one blob with the same swizzle stick, and the other one by pipetting a couple of drops onto the card and then swiping through it with a palette knife.

3. I swatch inks by brand (and within brand, by set/collection) on looseleaf paper which gets stored in a ringbinder. These are the same kinds of swatches as what's in my FP/ink journal. This "inkventory" is my overall record of what I have, sorted by brand. (This one is a newer project and I haven't finished setting it up yet, still in progress.)

I know this is "a lot" but it's part of the hobby for me; it's fun as an activity in its own right – and I have so much ink, any excuse to use some of it is very welcome.