Just cast off my evolution scarf, it took most of the year

I finished a double-knit throw last spring with moth and fern charts on it, so I know exactly that weird empty-handed feeling the morning after. Mine took about seven months of couch knitting and the first week after binding off I kept reaching for the bag next to the sofa and it wasn't there. It passes, mostly because you start sketching the next chart wether you meant to or not. For what it's worth, I used Cascade 220 on 4mm needles and the colour swap thing you mentioned was my favourite part too. My husband thought the reversed side looked better than the front, wich stung a little after all that work. On the solar system idea, go for it but think about scale early. Saturn's rings were the part that nearly broke me on a space-themed baby blanket I made for my sister, because rings and round planets mean long floats on one side if you're not careful. I found breaking the moons into thier own little chart blocks instead of one giant spreadsheet kept me sane. Also leave yourself way more background rows between motifs than feels necessary, my blanket got noticeably longer than my plan once it blocked out. Teal and cream sounds lovely with a nature theme, very museum-poster about it.

I did a deep sea charted scarf years ago, anglerfish and jellies and a squid running down the length, and I still haven't recovered enough to want another pictorial double-knit. Mine lives in a drawer now because I could never decide if I wanted to wear it or frame it. Two colours reversed on both sides sounds tidy in theory but every float tension decision haunted me for months, and I ended up redoing a whole eight inch section because one fish looked like it was melting.

The part that got me was charting. I used graph paper first, then redrew everythign in a spreadsheet when I realised my counters were wrong, and by the end I hated looking at cells of any kind. If you go for the solar system, maybe do the planets as bold shapes and skip the moons entirely. Ringed Saturn reads from across a room, a small moon does not. As for the hollow feeling, I handle it differently than a lot of knitters seem to. After my squid scarf I forced myself to knit three months of completley mindless stockinette socks before touching a chart again, and it reset something in my brain. Now I keep one dumb project on the needles at all times so the smart project never has to carry the whole relationship.

That hollow feeling never realy leaves, I'm afraid. I've been knitting since the early 70s and I still get it after every big project. Back in my day we charted everything on graph paper with coloured pencils, and honestly half my old charts are clearer than what I see on screens now, so maybe try pencil first for the solar system. One thing I never see discussed is binding off double-knit properly, both layers togehter so they stay joined at the edge. Half the ones I see finished have the two faces flopping apart at the ends.

Got to push back on the long floats warning from the moth and fern post. In double knitting you basicly don't get floats like you do in stranded work, the two yarns sit between the layers and swap sides at each colour change, so rings or wide shapes don't leave loose strands dangling anywhere. If anything a wide motif is easier in double knit than on a plain stranded piece. When I did a compass rose blanket the big solid circle was the calmest part of the whole chart. The real pain with round planets is stitch count math, getting the curve to actually look curved and not like a pixel blob.

What's your stitch count per repeat on those animal motifs? I ask because I attempted a dinosaur border scarf a couple years back and my t-rex came out looking like a lumpy potato at 20 stitches wide. Had to rip it back and give him forty, which then ate half the scarf length. Curious if you went bigger for the elephant especially, since trunks seem like the kind of detail that falls apart fast at small scale. Also can't blame you for missing it. I finished a big project once and immediately cast on something tiny just to have something in my lap, no shame at all.