Ok, I know that some tips are just general, while some are specific to the detectors I use.  I'll try to keep those separate.  If you have a tip you would like me to post, send it to me , and I'll post it here with your online name for credit.  Also, you might want to try the tips section of Mike's CZ Page .  He has many, many, more tips than I do.

General Metal Detecting Tips

• Don't just wander around.  Use a Grid Pattern.  Start a search by running East-West.  Once you have searched that area, switch to a North-South pattern.  Then to ensure complete coverage, run sweeps at a 45° angle to the prior pattern.  This will help cover any spots you missed earlier.
• Always, ALWAYS, recheck the hole after you retrieve your target.  Multiple coins in one hole are common, especially in areas where people can sit against a tree, or where they are knocked to the ground and rolled around (like tackle football).
• Always, ALWAYS, fill your holes!
• Carry a towel or a frisbee that you can put the dirt you dig onto.  This makes for a very quick cleanup of the hole, plus you don't leave any dirt on the grass that people can see.
• If you're just visiting a new site and/or scouting around, then go ahead and "Cherry-pick" the good targets.  However, if you realize that you will be coming back frequently, then start digging the trash.  This will ensure that you don't have to "redetect" that trash targets.  That trash might just be masking a good target beneath it.  Besides, if it reads as a pulltab, it might just not be a pulltab, but a gold ring.
• Speaking of gold, if you want to find gold rings, you have to dig those foil and pulltab signals.
• "Where there's Wheat, there's Silver. "  Basically, if you are finding wheat pennies, slow down!  There should be some silver dimes in there.
• "Indians Come in Tribes."  If you find one Indian penny, slow down, there are usually more.
• Regardless of machines, most Indian head pennies read as a zinc penny.  Therefore, if you get a zinc reading at 4" or deeper, DIG!
• Keep track of the sites where you've dug deep, old, coins at.  After a good rain, go hunt that site thoroughly!

CZ Tips

• To get a really tight pinpoint, rapidly push the pinpoint button several times while slowly approaching the target.  With practice, you can get a pinpoint that is the same size as the target.  Once I get this tight a pinpoint, I'll memorize the location by looking directly through the inner coil.
• Speaking of pinpointing, if the target is REALLY shallow, once you have reached this stage, you can either probe for the target, or use an electronic pinpointer to locate the target.  Then it's just a matter of popping the target out of the ground.
• If the area I'm searching is clean, I'll run in Auto-tune (all-metal) with my Sens. at 8.  Once I receive a target, I'll switch down to 0 Disc. to ID the target by sound.
• In trashy areas, use a 5" coil (commonly called the "Hockey Puck").  It will get right in there with the trash, and separate the good targets from the bad.
• When I'm using my 10 1/2" coil, I usually hipmount my detector.  I have a small carabiner-like clip going through a hole in my web belt.  I use this clip to run the cord for my coil around my back, so it doesn't get tangled up in front.
• Speaking of the 10 1/2" coil, I've found the best way to pinpoint shallow targets (in sand) is to use the "X" method of pinpointing.  Make a pass over the target.  Keep your eyes on the spot where you got the signal.  Now rotate around 90°.  Sweep the target again, along the line of the inner coil.  Where the two sweeps intersect, is where your target is.
• I recently dug a War Nickel that gave me "The Bounce" between "Nickel" and "Foil".  I've heard that Buffalo nickels will do this, and older "V" nickels and Shield nickels will ID as foil.  This is caused by the corrosion on the coin, as I understand it.
• If you're in an area you suspect has older, deeper coins, run your Sensitivity to 6 or 7.  This may cause a lot of false targets, BUT, any soft, deep, iron/coin bounces can be a deep coin.  Go slow and cover the ground thoroughly, moving forward an inch at a time.

Target Possibilities
This is something that I came up with myself.  I have made a table with the various segments of the CZ's meter.  Below those segments, I have listed possible targets that turn up in those segments.  I'm not going to list the targets that the segment is named for, that would be redundant.  Also, you might want to remember that the "correct" order of conductivity of targets is Iron, Foil, Nickels, Pullrings, Pulltabs, Zinc Cents, and High Coin.