Phonetics :

Phonetic alphabets were used in radio communications as early as World War I (1916), as aid to clarity of verbal communications. It was adopted in quick succession by the US military, NATO (North Atlantic Treaty Organization), and finally the ITU (International Telecommunications Union) in 1956. Phonetic alphabet is useful when calling distant station or when the band is crowded, or when for any reason the station called is expected to have difficulty in copying voice signals. For example, the letter 'D' in represented by the word 'Delta' in phonetics while the letter 'B' is represented by 'Bravo'. When actually operating on the bands, you will frequently hear other, locally-derived phonetics. In many cases, these are used to more clearly define a ham's callsign, using for example the word "kilowatt" instead of the standard "kilo". A phonetic alphabet is a great way of spelling things out in the presence of a poor signal. Where someone might not be able to understand single letters, they might be able to understand enough of a word to be able to determine what letter that word stands for.

For practicing phonetics you do not have to devote special time for it. It can be done while your are reading newspapers heading or when your are traveling in bus or train (looking at the advertisement hoardings and spelling it in phonetics). If you are well versed in phonetics it will be really very easy to copy stations much quicker which will help you at the time of DX pile-ups.