Upgrade to special delivery postage.
~what this means ~
My standard postage comes either first class or first class recorded (dependent on value of the order) Neither of these have a guaranteed delivery timeframe.
Special Delivery is guaranteed next day. 
Should you choose the postage upgrade this means that once your items are made, they will be shipped with a guaranteed delivery of the day after shipping and they will be insured for their full value.
This does not mean your items will arrive the day after you order them.