My secret is, i go for a couple of 8 minute sessions on the sunbed to give me a slight base tan, then i use factor 30 for 2 days, then factor 15 for 2 days and then factor 8 for the remainder of the week, i take the sachets of suncream so ive no need to worry about weight of bottles.
When i do the sunbed first i never burn anymore whereas i used to, i came home with a lovely golden colour, the boys at work all commented on what a lovely colour i had.