I use the siphon I made with air line tubing and chopstick to siphon them through a brine shrimp net, then rinse well in cool dechlorinated water and then I use an eye dropper to feed the fry.
Depending on the BBS hatching container, you can shine a flash light on it and the BBS will be drawn to the light to get them all in one corner to help with collection.
When feeding BBS try to avoid the shells as much as you can.
I only feed BBS when the BBS still have their yolk sac-otherwise they can have very little nutrition, this is important with under 2 week old fry, often you will see the fry spin down to the bottom of the tank and then die....this is usually due to poor nutrition.
Once the BBS absorb their yolk sac- I supplement them with HUFA (highly unsaturated fatty acid) I use a product called "Selcon" it is a saltwater fish supplement and BBS are saltwater critters. I don't start feeding my fry with the HUFA supplement BBS until after 2 weeks...only the NHBBS, plus newly hatched BBS are smaller and the fry can eat them easier.
Careful not to over feed with BBS, I watch my fry stomach and as it turns orange in color and look round-I know they are full
Its really fun watching the tiny fry eat too, even at such a young age they show lots of personality....
If you see black dots in their stomach, its most likely infusoria