I started last week, up till now around 8 tryouts. I began with only a few spoons. Now I use 8 table spoons + around 120ml (4oz) water. He can almost finish. Just that he yelled when the spoon leaves his mouth -- I guess he wants it non-stop like drinking milk (好無耐性)...
I can't let him sit 90' straight to eat because it spills out seriously. I let him sit like 45' angle. Probably later I will make him sit straighter a bit...
I am using Nestle baby cereal... tastes very good... it doesn't require extra milk powder.