I made some really cute collars for my dogs by hot-gluing choker-length necklaces to nylon collars. It's super easy. The hemp necklaces work really well. For tiny dogs and cats, use bracelets. I'm sure the stores have Valentine-themed necklaces out. Another idea is to just glue pretty fabric ribbon to the collars.

Mary Englebrieght's magazine had some neat things in it. Here's a website with some dog bows.
www.hotbows.com
Susan in Bama

Along the lines of Meghane's suggestion above...

Find some Valentine-theme ribbon at a sewing or craft store. Stitch it securely to nylon collars. Be sure to measure the collar width(s) before you go ribbon shopping. This would work for all sizes of dog and cat collars.

Another collar idea:
***For dogs, paint simple dogbones and hearts on nylon collars using decorative paint. For an easy dogbone, paint a straight line, then put twin dots at each end. Alternate with hearts.
***For cats, paint little fishies and hearts similarly.

Another collar idea (for cats or dogs): Just cut a length of sturdy holiday themed ribbon, fold over ends and stitch to prevent ravelling, then put corresponding spots of "hook and eye" stuff (Velcro) on each end. Much cheaper than using the nylon collars. If you can't find ribbon you like, consider using cotton or blend material... just make a tube, turn right side out and turn the ends in, press flat, stitch up the middle or each side and across ends to finish and to keep it flat. Finish with the Velcro spots. Make them in several sizes.

Note on collars: You may find that the pet owners don't really know what size to get for their dog or cat, so try some on various size pets beforehand and make a chart... an X" collar fits a cat, a Y" collar fits a MinPin, a Z" collar fits a Golden Retriever, etc. Then be sure the collars are labeled with sizes.

A toy for kitties: paint little hearts on two practice golf balls; glue one to each end of a curly shoelace. Or use pingpong balls; drill a hole in each ball, insert the ends of the shoelace and glue them in place.

Dog toy: Got some fleece or berber scraps in Valentine colors? Cut three pieces, 1" x 1 yd, or 2" x 1-1/2 yds, or 3" x 2 yds. Tie a knot in one end, braid, tie another knot - a braided shaker toy. (I took these instructions from a book... you might want to make one first to see which dimensions work best.)

Of course you can paint cute designs on plain dog and cat feeding bowls.

Make a batch of dog bone 'treats' recipe, and use a heart shape to cut them out! They would look really special if you put just one or two (depending on size) into a zip-lock sandwich bag and used Jacquelyn's Valentine Bag Topper for each one!

If you do computer crafts, make up some notecards with a cute picture or cartoon on the front with a related saying, like:
"Here's some dog-gone good news!"
"I'm letting the cat out of the bag!"
"Love me, love my dog"
"A house is not a home without a dog"
And be sure to put your group's colophon on the back. Package them up nicely, maybe a group of four cards and envelopes in a zip-lock bag.

I realize your fundraiser is for dogs, but I included cat items because many owners have both.

If you can get to your public library, there are many books available on making special toys, treats, gifts, etc. for dogs and cats.

Here is a link that might be useful: Holiday Bag Toppers

Thank you all for the great ideas. I certainly would not have been able to come up with those. They all seem easy enough that even I could do them.

Just a further note on "marketing" at your sale, Katsmah...

As you know, when you go into a store it is an item's packaging that usually gets your attention first, especially when you are comparing a couple of like products. As much as we are encouraged to go for the simple packaging to save the earth's resources, if one item is unpackaged and just has a price tag, and a second like item is nicely packaged with an item description, care instructions, etc., we'll probably buy the fancy packaging.

Same goes for the sale you have coming up. If you are familiar with 'bag toppers' [as Jacquelyn has recently posted], you can see that there is minimal cost involved (and the paper and ziplock bags are both recyclable!). But think if the eye-appeal!! Folks like to buy things that look nice!

Consider yourself as a shopper at your sale - would you be drawn to a basket with a jumble of collars in it (no sizes indicated), or would individually packaged collars with a cute picture, size information, etc. get your attention first?

Plan ahead. Decide what you will be making/selling. Locate some cute clipart you can use. Decide on the bag sizes you will be using... in addition to the standard sandwich size, there is a really handy 'snack' size that would be ideal for some of the treats, collars, etc.

Lay out the topper basic design, based on bag size(s). Save it/them. Then add clipart, catchy names for items, selling points, size, etc. If you don't want to use your colored ink, do it all in black and white, then use a colored marker to add a spot of highlight. Cardstock really works better than regular printer paper.

If computer crafting isn't your fort enlist the help of someone else who is comfortable doing it, and save your energies for other tasks.

Here's are a few selling points for the Velcro holiday collars... they are SAFER than regular buckled collars! If the pet gets the collar caught on something, the Velcro can be pulled open. They are easily washed. They are for dress-up (some folks like to put their pets in costumes).

As a side note, if you have some leftover material from other holidays (Christmas, Halloween, etc.), make up some collars from that, too. If it is left over, there will be almost no expense involved, and you could package them as Holiday Dress-Up Collars!

Thank you for the marketing tips. We will be competing with other rescue organizations for sales so the tips are appreciated.

I love holiday related things for my dog, Dakota. I just started making these collars. I bought clearance collars from Old Navy and cut off the actual collar and used the hardware and made my own. I've made several with the cutest fabrics.

Here's the Valentines one I made recently.

Candles. I bought the 3" white pillar candles. Used a small rubber stamp of a paw print, dipped in black craft paint and stamped the candles. I put 1 red heart on the candle. I printed on the computer on card stock a saying.
Wrap the candle in clear cling wrap with curling ribbon attaching the little saying. The little tag said. "A stray paw has touched your heart." The project costs about $1.25 each to make.