Watermelon….cut and seed watermelon and blend. If you want pure juice with no bits put through a seive to remove the pulp.
Tangerine….squeeze the juice from about 4-5 tangerines
Lime/Lemon….squeeze the juice from 12 limes and add 12 heaped tablesoons of sugar. Add to 1 to 1.5 Litres of cold water.
Mango…blend 1 ripe mango and add a little water to thin the pulp.