Use of grenades

[Dr Sadako]

Flashes
Avoid throwing 2 flashbangs in a row. Most players are prepared for that.
If you do throw both of them, throw one short and one long. The opponent being prepared for two flashes will turn instinctively at the second and will most probably be flashed.

The combinaton flash - HE - flash is also very effective in close quarters. The last flash is usually unexpected as there was a HE as the second grenade.

Fight flash with flash! If you know that the enemy is nearby and you notice the first flash coming in, get ready with a flash yourself (if you have backup). The second flash will most certainly come soon and will be followed by a rush. Throw flash(es), preferably before the enemies second flash, and fall back to a good position.

Smoke
The most important thing regarding smoke is that you should never throw it at your feet. Being in smoke reduces your options. I usually throw a smoke at a bottleneck of some kind and then pick the less usual camping spot to guard it. If the enemy goes through the smoke he will first aim at the regular camping spot.

Smoke is great to pin down the enemy for a while (used as an attacker). On inferno Ts could throw 2-3 smokes towards the left site (CTs right) and then keep rushing up the middle. The guarding CTs on the smoked side usually stay there 10-30 seconds and that should be enough to take over the other bomb site.

Grenades in defence
Defensive flash and smoke is key on some maps to stop a rush. Playing CT on dust2 is a perfect example. Bomb site b and the mincer is a regular rush zone right after spawn (as well as short A). Use flash, smoke, and HE to slow down the rush and buying time to get some backup. I regularly (when defending B) rush up either the ramp or stairs to mincer with a flash ready and I throw it in there as soon as possible.

HE - at the end of a round
I try to save my HE to the end of the round if possible. Then the opponent usually has lower health and the HE is more effective and usually lethal. The best thing is that it is in most cases unexpected.

[OldBloke]

HE - at the end of a round
I try to save my HE to the end of the round if possible. Then the opponent usually has lower health and the HE is more effective and usually lethal. The best thing is that it is in most cases unexpected.

That is such a useful tip. Most players are too keen to chuck their HEs at the start of the round and often when the enemy hasn't even been seen.

Save 'em for the end when there's more chance of them killing than injuring your opponents.