hi mate, ive played at amature level in goals and i always get picked in goals at 5`s cause i never seem to let many in. the only advice i can give is always be aware of your position between the sticks and make yourself BIG when one on one with a striker. goalkeepers are different when up against corners , some stay on there line while others attack the ball. ive always been one for comming out and collecting the ball from corners but just make sure if you cant get two hands on the ball at least make sure you get a strong fist on it, dont worry whos head is in the road just go through everything.
hope this helps a little ....good luck