It all depends upon your situation: are you planning to stay in your home for the long term, or are you looking to get out of the property you are in for a good return on your initial investment?
And, depending which sort of variable mortgage you have, the rate you lock in at will usually be higher than the rate you are paying now.
Your negotiating ability with your bank will be largely related to your credit score, so, while you are earning money to pay your mortgage, also ensure you always keep your small amount of bills either paid off or up to date.
It's all a big, connected circle. Due diligence with your finances ensures you, and therefore your bank, more flexibility when negotiating mortgage rates.
And, always ensure you ask for the lowest rate they are offering at the time when you are ready to lock in. It can be negotiated - but you must have some power...back to the due diligence on your credit. And remember, you are the customer.
