I think the most important thing to do is remove dust - once or twice per year is all that's really needed (at least in the case of an adult collector; Children's bears can be another story). I use the brush attachment of a vacuum cleaner, and of course you need to take care not to dislodge eyes or ears or muss up embroidered noses.
The dust removal is important even if you plan to brush teddy since the dust will act as an abrasive otherwise and damage both the fur and backing fabric.
We use a soft hair brush like the kind used for babies. Of course, we buy it new and never use it for anything else except Bears.
Brush very gently in short strokes. Technique often varies by the Bear.
Short fur can simply be brushed in the direction of the fur. Longer fur might need to be brushed against the nap then brushed down.
As you have mentioned, if too much fur comes off in the brush, stop.
You are bound to get a small amount of fur coming off on just about any Bear. It's part of the manufacturing process. The way plush is made, there are bound to be loose hairs.
For dusting a lot of Bears, we often use a vacuum cleaner.
Use a canister style vacuum with a long hose.
Here's our trick:
Get a cardboard tube such as one from the center of a roll of bathroom tissue.
Cover one end with a piece of cheesecloth and hold it in place with a rubber band.
Poke a small hole, about the diameter of a pencil, in the side of the cardboard tube.
Place this assembly over the end of the vacuum cleaner hose. Hold it on with a piece of duct tape if necessary.
Now, you have a cover over the end of the vacuum hose to protect your Bear from getting his fur or ribbons sucked up.
Place your finger over the hole in the tube to regulate the amount of suction.
If the suction is too strong, let the hole be open. If you need more suction, cover the hole.
If I'm doing just one or two Bears, I often simply put my hand over the end of the vacuum hose and let the air go between my fingers. I use my fingers to fluff up the fur and the vacuum sucks up the dust.
We clean and fluff our Bears about twice a year. We start at one end of the Bear's Den and do a few at a time. By the time we finish all 1,000 of them, it's time to start over again.
No! That's not a typo! I said, "one thousand!" That's a lot of fur to keep clean and fluffed but we enjoy talking to the Bears as we do. They like the attention, too.
I use a variety of implements for that, depending on what type of fur and exactly what I'm trying to do with it....a wide tooth flea comb is great for de-tangling and straigtening long fur, a regular SOFT bristle hair brush is great for general purpose brushings, and a steel-bristle slicker brush is great for teasing fur to make it fluff straight out.
for dusting, I use a cheap 2-way shop vac (has two ports, one "In" and one "out" that you can plug the hose into) I use the out (blow) direction ONLY, and the vacuum itself is reserved ONLY for blow-dusting bears, for obvious reasons.