You will often be asked to arrive at the head with a yard or two on. This will be intended to move the jack, promote a bowl of your won side or push out a bowl from the opposition.
When working out the line you need to take for this you should think about how much your bowl turns in the last yard or two so that you arrive at the head with the yard on
You may alternatively be asked do a positive draw which will be similarly weighted but may be without the need to tighten the line. The key here is that your skip does not want you to be short!
Top Tip: When you get chance follow your bowl down to the head. The way your bowl finishes can look very different at the head from the mat! Remember that you should be at the head by the time your bowl finishes and if it is in a competition/league to check the rules around how often you can visit the head.