Getting a cross for OLL is the slowest part for you?????
During the last couple of moves of the F2L you should see the number of correctly oriented edges. This is the most likely thing that will happen:
0: You will end up with 0
1: You will end up with 2. The 2nd one will become correctly oriented during the last 1 or 2 moves so you should be able to see if you get the "small L" or the "line". But 0 edges is likely to happen if the correct edge is on the side that your last move will be (R probably)
2: You will end up with these 2.
3: Same as with 1 edge, but 4 edges is likely to happen if the 3 correct ones are not on the side that your last moves will be (R probably)
4: That's strange, F2L must be done already
Orienting 2 edges should be done in 2 seconds, even if you are not a really fast cuber. Orienting 4 edges takes about twice as long for a beginner.
If you want to speed up your OLL, this is what I would do:
First learn these:
0 edges: 1 out of 8 cases
2 edges: 2 out of 42 cases
4 edges: 7 out of 7 cases
then learn these
0 edges: 8 out of 8 cases (low occurence chance, but you eliminate your worst cases)
2 edges: All cases with < 9 moves (high occurence chance, big time-win)
4 edges: You already know them all
Then learn all other 2 edge cases