The following are not the definitive answer to the problems.
They are designed to be a bit like a sticking plaster which just may help until you get to your Coach.
Not much good however if you need stitches or maybe even more intense treatment.
1. Playing Heavy
Slow down, just move slower and reduce the speed of your delivery, speed comes from velocity, your creating this so reduce it and the Wood won't travel so far.
2. Playing Short
Move quicker, simply increase the speed of your delivery.
Practise this to find the right level for you before you try it in a match.
3. Playing Narrow
Ensure your whole body is committed down the line your trying to play.
Have you picked the shoulder? (the point at which the Wood should start to turn)
Are your eyes, feet, whole body pointing at the shoulder?
Bet you're looking at the Jack!
Simply turn your whole body more, not a half turn with your feet pointing elsewhere.   
Stop looking at that Jack (Jackitis), Look and aim at the shoulder.

4. Playing Too Wide
Again, ensure you are addressing the line down to the Shoulder.
Ensure you "Step Down This Line"
You may be stepping out too far to the side.
You may be "throwing your arm out"
 It should be a smooth pendulum action down the side of your body.
Again it could be as simple as turning your body less.
Also, watch what shoulder other player's successful Woods are turning on.
You may be over compensating for your Woods. Try their line.
(Be careful that they're not left handed and your right handed, different line altogether)
5. Delivering the Jack into the Ditch
Too many people just "Cast the Jack" up the green in order to get on with the match.
This is a disaster waiting to happen .
The control of the match rests with the person who controls the Jack.
This is undoubtedly the most important delivery in every single end and should be treated with more care and effort than any wood.
Great care should be taken with the grip and delivery of the Jack.
On very fast greens it's possible to bowl the Jack across the Green to one of the corners of the rink, the principal being that the greater distance will take some of the weight out. Scientifically sound but not a great base to build your long term game on.
Don't treat the symptom but tackle the reason for the disease by learning how to control the Jack on all types of Greens.
6. Trial Ends "What's the Point?"
Sad development creeping into the game.
The learning about the green, your opponents & your colleagues, starts from the first trial Wood. You and your Skip should be learning with every wood that is delivered.
In some Counties they ensure they play Drawing, Running, Firing, Edge of the Ditch and various different lines, all in the trial ends.
Each person in the rink has a job to do even in the Trial ends.
The Skip should start the first competitive end with the information on the green gathered from the delivery of 16 woods from their own team, delivered to their instructions.
They also have the information gained from watching their opponents 16 woods.
Not only will they have Green information but may have started to formulate views on strengths and weaknesses in each of their opponents that they may confirm early in the match and exploit to their advantage.
Each player should also have been watching their direct opponents Bowl and started to formulate similar views.
What is the point?
 Absolutely none unless you use them and don't just treat them as a tradition.
7.Bumping Your Wood
Can be very embarrassing, particularly if you mark the green or even worse "take a divot" on an outdoor Green.
The reason is very simple, you are releasing your Wood too high up.
You need to get closer to the Green and release it so that it simply runs off the ends of your fingers along the Green like it was on silk.
Easy to say but not always easy to achieve because many a time it's caused by physical conditions which make it difficult to get down low enough.
Simple little test we use in many of our classes that you can try.
Put a £10 on the ground in front of you at approximately where you would normally release your Wood. Pick it up. If you can, we can help you stop bumping your woods.
If you can't we can help you develop a delivery that is easier for you.
Why bother if it's successful.
The problem is that when you bump it takes "weight" out due to the result of the impact on the velocity of the Wood.
You may have learned to compensate for it however be aware some Clubs have large signs stating that if your perceived to be damaging their Green you will be asked to leave it, irrespective of the competition.
A trained Coach can help you cure it once and for all.
If you have a video camera film yourself, stop it on freeze frame when the Wood actually leaves the tips of your fingers.
There should be no discernable space between the Wood & the Green.
If there is then watch it skip like a flat stone across water.