Java moss - spead some over the bogwood water and then tie with cotton thread. leave for about 3 weeks, choose to remove the thread or leave it until it rots off
Java fern - same as above
Riccia - cover with a hairnet type setup and riccia will grow out and cover the hairnet so you dont see it (requires co2 injection and high lighting)
anubis nana - basically just place it on bogwood like the java fern and tie down with cotton... the roots will then attach to the wood. Just requires the rhizomes to have free flowing water around them. hardy plant aswell
if your starting out try the first two, they are pretty undemanding and the java moss will grow fast
I think there is christmas moss too...i have no grown it so dont know proper procedure
I'm not poo pooing AE but with Riccia I don't think its possible to get a bad bit. If you put nearly dead Riccia floating it will be glowing after a couple of days under bright lights and ebay is really cheap.
OR
I have a huge amount in a sandwich box on the windowsill at the moment waiting to go on ebay but I could sell it cheap.
It is a mix of Fluitans and Dwarf and was floating to help me in my first week of highlight but it grew so fast.
In all there is probably enough to sell as 2 tennis ball size at £5 each or 10 golf ball sizes at £2 (Royal Mail post included)
pm me
p.s. It is possible to carefully pull the Fluitans out from the dwarf if you wanted as Fluitans is twice the size