If you're just starting to get into flyfishing, and maybe just starting to tie flies also, the easiest to tie fly that is effective for both species would be the woolly bugger. For chums your can try colours like red, pink, chartreuse, and black...or different combinations of those colours. For coho, I would stick to olive, brown and black, and in smaller sizes. You can also tie flash flies like the Christmas Tree and the Muddler Minnow...but for the Muddler, I tend to skimp on the deer hair and put a lot more Krystal Flash. Don't be afraid to use a stout streamer hook for smaller coho flies. Good luck.