I'm officially useless, but I'll try and help nonetheless. Practice mode is quite useful to attempt some stuff.
Ok, idea #1: Get the goalie to leave his posts. On his line, the goalie can save a lot of shots. However, while he's running out (and before he actually gets to the ball), he's vulnerable. So a typical KO2 goal is to trap the ball (which wastes valauble time, but is easier for beginners, I believe) in the "sweet spot" pretty much in the middle between the edge of the box and the penalty spot. This will draw the keeper out and thus give you a good scoring chance. Trapping makes this easier because you then have more control over what you're doing next. A standard variation is to take a step to one side and then shoot it straight into the net. Another is to take a couple more steps and shoot it diagonally into the net. I'll draw up a diagram if you need it.
In fact, alone vs the goalie it's really quite simple then to just walk the ball into the net if you like. Drawing the goalie out can work in a number of ways. Try, for example, to just run into the area diagonallyand as the keeper is coming out, to simply shoot. This works better if you leave the ball a bit of room - so "tap it" and leave it running ahead, give the ball just a bit of space, you'll catch up with it again. The keeper will save it at times, but you'll get the right idea: If the keeper is on the move, he's more vulnerable.
idea #2: The opposite. If the keeper thinks he can catch the ball on his line, he'll adjust himself accordingly and just stay there. Be there before him and you'll score. This is obvious with headers after diagonal crosses. So find the right spot for a diagonal cross that the keeper can save at the far post - and be there with your striker in the middle of the goal mouth first - whether you then shoot or head it straight ahead, it's rather seldom that the keeper can still save it. It doesn't need to be a cross - if you can intercept a shot towards the far corner (needs a bit of luck/possibly skill, don't aks me) it'll have the same effect.
idea #3: Lobs.
The art of lobbing has a simple goal - it needs the right height so the useless keeper can't save it. The sweet spot as far as I can tell is not right below the bar (he will jump up to save that), but just over his head. Theoretically, you can lob from straight on (perpendicular), from the diagonal or even near the corner (parallel), though that'll need a bit of aftertouch. Of course, using aftertouch means there are theoretically lots of places to lob from, but you'll have to get it just right and some players (like Barrett and Scott) who can't really shoot straight will need a lot of luck to get it right. This is really a question of timing. Personally, again, I find I have better control if I manage to trap the ball first. This goes especially for the shorter diagonal lobs from just outside the area.
idea #4: Exploit the goalie's weakness on the Barrett side (the goalie's right as seen from his point of view). Basically, try the following - run into the box diagonally from that side (preferably not with Barrett himself, but even he'll do the trick) and shoot when you reach the six yard box, not sooner. Try it a few times and you'll see what I mean. And generally shots into that corner of the goal have betetr chances of going in than from the other side - though the latter is certainly not impossible.
idea #5: A curled shot into the goal from near the goal line. As seen on the big screen.
This shot is troublesome for the keeper, especially if it is very low (will go beneath him) or fairly high (will go above flying Fischer, something Spyros can do but I cannot), or if it curls just into the near corner or of course, if the goalie is even behind his goal. For that latter, he'll have to believe the ball is running too far and will end up as a goal kick. Similar to what I said towards the end of #1 you can practice giving the ball some space, tapping it ahead and waiting a fraction of a second to chase it (not the usual "tap, tap, tap"). You should be able to see how the goalie ends up in his net and if you then manage any curled shot before the ball runs out for a goal kick, it's pretty much a certain goal.
Try those and then return for more ideas.