I have provided some small tips which will be useful i guess..
#1. In TSO we have the most recently viewed dataset using REFLIST like that we have a way in which we can view the recent files used in file aid.
When you come to the file aid main menu. Give the browse option which will be 1 and then make no entry in the dataset to be browsed and hit an enter. You will be able to see the recently viewed files through file aid.
We can select them by giving S against the file name. If you mapped the same file with different layout. It will give the option of selecting the layout in the next screen if there are more than one layout.
#2. Map the data in FMT mode with some copy book and you can see the field' s offset, picture clause, field number& field level
Field's offset ->Give show offset or S O
Field's picture -> Give show picture or S P
Field's number -> Give show number or S N
Field level -> Give show level or S L
#3. Using file aid you can know the count of the file. Enter the option 3.8 from the main menu. You will be thrown a screen in which enter the file name alone and also enter the disposition mode as SHR. Then hit enter you will be thrown a screen in which enter TALLY which will count the number of records in the file. Then you can enter END to return to the main screen.
#4. Search and Replace option with file aid. When you want to make a mass replacement in a PDS for particular field. Use this method. Hit 3.6 from Main menu and in the screen thrown enter the dataset name and in the option enter U. Again a screen will be thrown in which you will be asked for the option thru JCL or not. Then you should enter the name you want to change and the name which you want to be replaced. This will show the places of updating for confirmation. If we give as N as option in Confirm changes. The update will not be made.
Expect more. If you have some document which you feel will be more useful. Please share it across