Jigsaw puzzles are another old hobby of mine. I've always enjoyed putting them together, and I even have a couple that I did of Norman Rockwell paintings framed and hung up. That's less following directions and more pattern recognition, but it's still taking a bunch of pieces and putting them together into a whole.
Lego has been a major hobby of mine. Not so much in recent years, but in college and for a few years I was massively into the Star Wars Lego sets. I've got a couple dozen probably, ranging from the A-Wing fighter up to an Imperial Star Destroyer. I don't buy sets very often these days, but I did just pick up the Mirkwood Elf Army on clearance. My wife is much less likely to give me the look when they're half off.
Lego Thranduil does not approve
I'm not allowed to put the Elf Army set together, however, until I've finished my current project. A little over a year ago, my wife and I went to Japan for a week and a half, and one of the things I brought back was a paper craft model of the hat shop from Howl's Moving Castle. It took me a while to get around to translating the instructions to be sure I wouldn't mess anything up, but I finally started putting it together a little while back, and I'm down to the last few decorative bits.
Once that's complete, and I've put together the Lego set, I'll need something new to build. I do have a model U-boat I picked up a while back in Chicago. Maybe that'll be the next project.