Jeanne: maybe this will give you some ideas! Have fun!
It's ultimately up to you! First, what sort of style is the daybed? What's its main function? Seating, with sleep option? Decorative? Where is it in the house?
If the daybed is a certain style, you probably want to use that as a foundation. It's not against the law to put ultra sleek and modern treatments on an antique daybed, with wrought iron back and sides; it would just take a seriously talented, insightful and visionary mind! And, for most, it wouldn't be appealing, even if it "worked".
A basic daybed can be styled in any manner you choose, but function should be considered. If it's going to be used nightly/daily, to actually sleep on, you may wish to avoid burying it under lots and lots of decorative pillows and throws, that you'd have to remove, then replace, each time it's used as a bed.
If it's primarily for seating, then pillows and throws are welcome, but don't forget that once in a while, they may need to be moved for someone to sleep on it. If it's purely decorative, you can gather any number of soft goods to put on it.
I'd start with using things you already own, just to play around with arranging them. The good news is that nothing here is written in stone! If you do decide to buy some things to use, keep the tags on, and the receipts. What may seem like a good idea in your mind, may end up being something that in reality, you want to return, ASAP!
If the daybed is in a communal room, then you'll want to take the colour schemes in mind, but it does not have to reflect the style of the room. You can set up an "oasis" of, say, Romance, in a, say, Modern styled room, but this is not something I'd suggest for a newbie, as it's a bit complex.
In your room/kids room, then the suggestions above are far more lax. Make the occupant of the room happy! Life's too short to make ours aspire to House Beautiful. Make them House Happy!
Here are some images that popped up, when I googled your question. Scrolling down, there are other options to look at, as well. Best wishes.
I’d make sure the back pillows were double thick or even “bolsters” for it to function as a sofa.
If you have boosters custom made, stick with a neutral fabric, so that when you want to change the color scheme, you just buy a new bedspread and the pillows don’t have to be modified.
Throw pillows can be more dramatic, because they aren’t typically custom made, like some bolsters.
It's going to depend on the style you've got in the room already, the colors, and the goal you have for the daybed, if it's used often or not. Pillows and throws are quite typical.
Hi Jeanne, hope this gives you some ideas
You could drape a Victorian shawl over it and add a Roll Bolster, maybe with Buttons at each end or a tassel........Sounds very grand!
Lots and Lots of different pillows!
Hi Jeanne - YES! Lots of pillows. And a beautiful throw or blanket. Hope this helps with some inspiration. Hugs, Holly
I style with pillows like a couch!
Large quilt down to the floor and then pillows all across the wall