I'm not sure I understand the question correctly, but here's my take:
DO try to roost birds in the evening if at all possible,...unless you know where they are to begin with.
DO make sure you are trying to do it at the right time.
DO feel free to use a locator call, but use the right kind and at the right time.
DO understand that if you do not use a locator call, a turkey will not gobble at it.
DO understand that, in some places, you are really handicapping yourself by not using a locator call.
DO understand that effective locator use is an art in itself and you have to learn to do it properly and with the right tool.
DON'T try to get too close to roosted turkeys once they are on the roost in the evening.
DON'T overdo the use of a locator. Get them to gobble once, if possible, and stop.
DON'T assume there are NO gobblers in an area if they do not gobble or respond to a locator. Some places, gobblers rarely gobble in the evening. Point: know the tendencies of the gobblers in the area you are hunting.
DON'T assume there ARE gobblers in the area if they do not gobble to a locator. Some places, gobblers will readily gobble to a locator in the evening, and in some places the gobblers are a LOONNGG way between. Point: in some places, you are wasting your time if you hunt where you didn't hear any gobbling or get a gobbler to respond to a locator call the evening before.
DON'T use a locator call in areas where you know there are other hunters close by. Be courteous to your fellow hunters.