Shellac over Danish oil should be no sweat. It's a great finish and easy to apply (if you know the secret handshake). Instead of pestering you for a bunch more information and getting involved in a protracted ASCII-art USENET trouble-shooting marathon (fun when talking joinery but with finishes we usually just end up losing hair and/or patience and find ourselves muttering to inanimate objects... wait, I do that already), houseabout you pick up another piece of scrap and try this little trick, which has yet to fail yours truly. I'm a big clumsy no- talent galoot, so I'm sure an erudite, astute fellow like yourself can pull it off no problem.
First off, for our purposes, we want to employ the Danish oil to achieve what my dear friend, the late great Paul Radovanic (I sometimes called him Rayovac, just to try to get his goat, it never worked) called, "the greasy paper bag effect." That is, the translucent effect a leaky ham sandwich had on your lunch bagback in grade school, a very thin application of Danish oil can have on a piece of maple. I cut the oil with turpentine or mineral spirits (paint thinner, Doug) - 1:1. Brush or wipe it on, let sit for a minute or two - not the recommended 10 - 20 minutes, and then try to wipe it ALL off. If you're working on an open-pored wood, you might get some oil weeping back out of the pores. Sop it up as best you can.
Let the oil dry 24-36 hours (I sometimes don't let it dry at all, but I'm not going to recommend this).
Cut your shellac to #1.5. This should be plenty thin for wiping, which is what I always recommend for beginners. Heck, it's what I recommend for everyone. Yes, you can brush shellac. Yes, beginners can brush shellac. Yes, beginners almost always have a spazz when attempting to brush shellac, especially thick cuts. Don't ask me how I know this. Take an old sock; wool or cotton will work. Get a piece of an old pillow case or table cloth and wad it around the sock, pulling it tight so there are no wrinkles on one side. Dip it in a bowl of your #1.5 cut of spiffy shellac. Squeeze it out until it's just damp. You're wearing vinyl gloves, aren't you? Good. Now wipe the pad on the scrap. Take s short break. Count some nose hairs in the back of a finely polished chisel blade. Then wipe some more. Repeat.
When the pad begins to streak, do the dip-and-squeeze trick in your bowl of shellac. When the pad begins to stick to the workpiece, use a couple drops of mineral or raw linseed oil on the outside of the pad to lube it. When the shellac is dry, the oil will clean off with mineral spirits.
Let the shellac dry a couple days, come back, and mebbe one of these geniuses will tell ya how to rub it out to a glassy or satiny sheen... whichever is yer fancy. If we can't locate a polishing genius, well then I'll be back. Best of luck.