Practise, study, review your games... So much, so obvious.
But I also recommended a book as a good
MOT
:
Ray Cheng, Practical Chess Exercises
It offers you 600 positions (in sets of 8) for 'solving', so one of
them
will be a snap mate in 2... but among the others we might find
something
that looks like a mate in 2 but will fail because of some horrible
smelly trap, or a delicate endgame finesse, or a promising attacking
position where the best move is actually to win a pawn, or a position
where the 'solution' is to avoid a haymaker coming your way, or a
deeper
tactic that takes a deal of head-scratching, or a positional coup...
The exercises are graded in difficulty from one to four, and most sets
include one at each level. I guess this as close to practical play
as a book can get: you are faced with a variety of challenges, some
straightforward, but some rather less so; sometimes you enjoy the
chance
to attack, at other times you have to defend, and you'll never know
what's coming.
P.S. Apparently
John
Nunn's Chess Puzzle Book also gives 250 mixed positions (which I
can guess are tougher) but it seems to be out of print at the moment.