If you are having trouble finding cervical fluid, doing kegel exercises (tensing and relaxing the muscles that control the flow of urine) may help to push cervical fluid to the vaginal opening and make observation easier. (Avoid doing kegels within the first half hour or so after intercourse though as this could push the semen and therefore the sperm away from the cervix, which is exactly where you want them to be). Exercise and bowel movements also push cervical fluid to the vaginal opening making observation easier. You may find that the best time to check your cervical fluid is after a bowel movement.
If you do not see fertile cervical fluid externally, you might want to to try checking internally. (Use clean fingers with clipped nails and try to "scoop" it close to your cervix). You may actually find that you have some up at your cervix where it really counts. If you still do not see any fertile cervical fluid, your first step is to make sure you are not dehydrated. Drink plenty of water and, unless medically needed, avoid products such as antihistamines that can dry up secretions.
When cervical fluid is scant or absent, it is more important to try to time intercourse for as close to ovulation as possible, since sperm will not be able to survive as long while waiting for the egg to be released.
If you consistently notice that cervical fluid is scant or absent and you have been trying to conceive for a few cycles or more, then this is something to mention to your health care provider. Your charts may help your doctor identify where the issue lies (if there is one) so bring them along. It is best to consult your health care provider before trying any kind of remedy to try to increase your cervical fluid.