I don't recommend charting the warrant itself as time decay will play havoc with trend-lines and indicators. Plan your trade on the underlying share and then use an options-/ warrant calculator to determine what the warrant will (might?) be doing for the given scenario.
With covered warrants you loss is limited to the initial capital invested, so if you invest £1,000.00 in a covered warrant you can not lose any more.
The logic is that a covered warrant confers upon the buyer the right (not obligation) to buy/sell the underlying asset at a set price at a set date. So if the covered warrant is out-the-money at strike you decline the right to exercise and lose only the initial investment.
Further you can go short by buying a put warrant which is the right to sell the underlying asset - hence the put increases as the underlying decreases.