Creating a risk assessment template is pretty straight forward as long as you understand what you are trying to achieve. It needs to be kept simple but carry enough information so that it's a useful document and not just a tick in the box to get you a job or in to a scheme.
Task: What is it that you are going to be doing, for example. The use of a step ladder.
Hazard: What are the associatied hazards - there will probably be more than one, for example. Falling from height, being hit by falling tools. Keep in mind these are potential hazards than can effect anyone. You, your employers, your customers, people in the street etc etc..
Risk and severity: This is where you see a lot of forms vary considerably. Some people just combine risk and severity into one section and use a rating of low, medium and high, others use more complex systems of 1 to 5 for risk times by 1 to 5 in severity to give you an overall score (way to much hassle). All you need to do is be aware of the risks and severity and come up with a way of demonstrating that. The simplest system is the one I would go for.
People who could be affected: Straight forward enough. Employees (includes yourself), Contractors, Public (includes customer).
Control measures: What can you do to minimise the risk and severity. For example, ladder training course, appropriate ladders for the tasks, hard hat, second person to support ladder, use of tool belts, not putting tools on rungs, warning signs etc etc....
Residual risk and severity: If all your control measures are in place, how likely are the hazards to occur now and will the severity be the same?
The hardest part is getting your head around what the risks are and what your control measures should be as sometimes there are a lot more than you first think of and often you will only figure them out when one of your workers phones you up and tells you he has a screw driver sticking in his ear.
One thing I hate about other peoples risk assessments is that they are often incomprehensible except to the person who wrote them. These are documents that people need to fully understand. Avoid abbreviations. List BSEN standards on any recommended PPE. I always treat a risk assessment as a work procedure with a vew that if Joe Blow walked in off the street and picked up your assessment - would he understand it and be able to act upon it. Simple test, give it to friend or family member who isnt involved in the industry and see if they can comprehend it.
In regards to writing too little or too much. Too little is potentially dangerous and can put peole at risk by not conveying what you need to convey. Too much can be a pain to read but is much safer - as long as you don't over complicate things and confuse people.