Beading needles tend to be much thinner than embroidery needles. The main requirement is that they go through the beads that you are using with room for the thread as well.
I use small glass seed beads and bugle beads in my designs and I find that a size 10 English beading needle works well with these. The consequence of a thinner needle is that it becomes harder to thread. It is best to keep to single stranded threads when using a beading needle. Multi stranded threads will be hard to get through the eye of the needle as one of the strands will insist on not cooperating.
I find the best way to get the thread through the eye of the needle is to hold it as close to the end of your fingers as possible. Move the eye of the needle on to the thread. This is easier than the usual way of pushing the thread towards the needle.
There are needles designed to be thin and easy to thread. These have a twisted wire body and a lager eye that collapses when pulled through the bead. I find the needle too flimsy to be useful for card embroidery. They are great for stringing beads but not so good for passing through the holes punched in the card. I am sure they are fine when you get used to them and maybe I should persevere. I would be interested to hear from anyone who has mastered these needles.
The picture above shows a size 10 embroidery needle at the top, a size 10 English beading needle below this and a twisted beading needle with a larger collapsible eye below these. I have included some 2mm seed beads and 7mm bugle beads as a comparison.
When using a beading needle it is important to keep the pricked holes small enough, otherwise the needle is likely to fall through it and may drop off the thread.
Fine needles are easily lost when you put them down. I use a square of black foam rubber to stick the needle in when I have run out of thread. That makes it easy to find when I am ready.