Do not use grease on the battery terminals, make a mixture of baking soda or meetha soda and petroleum jelly then apply it on the battery terminals after cleaning them up with a toothbrush and detergent soap.
Always make sure that your negative cable is clean from rust or gunk - if in doubt use sandpaper to clean the body and lug then use a star washer in between the nut or bolt (the star washer bites into the metal when tightened)
Ideally your negative should be run directly to the transmission case or on the self starter's mounting ear - and branched to the cars body. All lugs should be copper, brass or non-corroding metal and should be soldered to the wire then heatshrinked.
Your positive should be a shiny clean connection to the starter and the alternators main (if setup thusly)
nearly 90% of startup and charging problems are due to insufficient negative connection.
If you have a stereo amplifier in your car - PLEASE for the love of God use a heavy duty fuse to connect it to the battery positive.
Another thing I like is to branch a thick (8mm) core negative wire to use for the radiator and condenser fans (rather than share a common ground point from the body and heating it up). Really helps them pick up some good speed.
All body points should use di-electric gel for negative contact (buy it from a specialist store in the parts market - cost about 200 bucks for a small tube)