If you are going to lift your ball under a Rule and the Rule requires that the ball be replaced, you must put a ball-marker behind the ball before you lift it.
When you drop a ball, stand erect, hold your arm out straight and drop it.
If a dropped ball hits the ground and rolls into a hazard, out of hazard, more than two club-lengths, nearer the hole or, if you are dropping away from an immovable obstruction or ground under repair, etc., back into the obstruction or ground under repair, you must re-drop. If the same thing happens when you re-drop, you must place the ball where it struck the ground when it was re-dropped.

Rule 21 -- Cleaning the Ball

You may usually clean your ball when you are allowed to lift it. Except on the green, you may not clean the ball when you lift it for identification, because it interferes with another player, or to determine if it is unfit.

Rule 22 -- Ball Interfering with or Assisting Play

If another ball interferes with your swing or is in your line of putt, you may ask the owner of the ball to lift it.
If your ball is near the hole and might serve as a backstop for another player, you may lift your ball.

Rule 23 -- Loose Impediments

Loose impediments are natural objects that are not growing or fixed -- such as leaves, twigs, branches, worms and insects. You may remove a loose impediment except when your ball and the loose impediment lie in a banker or water hazard. (Exception see Rule 12)

Rule 24 -- Obstructions

Obstructions are artificial or man-made objects. Bottles, tin cans, rakes, etc., are movable obstructions. Sprinkler heads, shelter houses, cart paths, etc., are Immovable obstructions.
Movable obstructions anywhere on the course may be removed. If the ball moves, It must be replaced without penalty.
You may drop your ball away from an immovable obstruction if it interferes with your swing or stance. Find the nearest point not nearer the hole where you can play without interference with your swing or stance. Drop the ball within one club-length of that point. (You may move your ball away from an immovable obstruction if it Interferes with your swing or stance.) Note: You should not pick up the ball from an Obstruction until you have established the nearest point of relief.

Rule 25 -- Where The Ball Lies

Casual water is any temporary puddle of water caused by rain or over watering. Ground under repair is any damaged area which the Committee has marked as\ such.
If your ball or your stance is in casual water, ground under repair or a burrowing animal hole, you may either play the ball as it lies or find the nearest place not nearer the hole which gives you relief and drop the ball within one club-length of that place.
If you ball is in casual water, etc., and you cannot find it, determine where the ball entered the area and drop a ball within one club-length of that place without penalty.
If your ball is on the wrong green, find the nearest place off the green which is not nearer the hole and drop the ball within one club-length of that place.

Rule 26 -- Water Hazards

Water hazard margins are identified by yellow stakes or lines. Lateral water hazard margins are identified by red stakes or lines.
If your ball is in a water hazard or a lateral water hazard, you may play it as it lies. If you cannot find it or do not wish to play it, add a penalty stroke and drop and play another ball from where you last played or drop a ball behind the water hazard as far back as you wish. If you decide to drop behind the hazard, drop the ball so that there is a straight line between the hole, where your ball last crossed the hazard margin and where you drop the ball. If your ball is in a lateral water hazard, you may also drop a ball within two club-lengths of where the ball last crossed the hazard margin, no nearer to the hole.

Rule 27 -- Ball Lost or Out of Bounds

A ball is lost if it is not found within five minutes after you first begin to search.
A ball is out of bounds when all of it lies beyond the inside line of objects such as white stakes, or a fence or wall that marks the playing area.
If your ball is lost or out of bounds, you must add a penalty stroke to your score and play another ball from where you played your last shot.
If you think your ball may be lost or out of bounds, you may plan another ball (provisional ball) from the place where your first ball was played. You must tell your opponent or fellow-competitor that you are playing a provisional ball and play it before you look for the first ball. If you cannot find your first ball or If it is out of bounds, you must count the strokes with the first and provisional balls, add a penalty stroke and play out the hole with the provisional ball. If you find your first ball in bounds, continue play with it and pick up the provisional ball.

Rule 28 -- Ball Unplayable

If your ball is under a tree or in some other bad situation and you decide you cannot play it, add a penalty stroke and do one of the following: Go back to where you played the last shot and play a ball from there Measure two club-lengths from the unplayable lie, drop a ball and play from there Keep the unplayable lie between where you drop the ball and the hole, go back as far as you wish on a straight line and drop and play the ball.