This is where the mighty Hellwolf comes into play too
. First, consider your matchup... what are you facing? You never really want to start with the Shadow Hunter, he is more of a second hero unless you get hex. I traditionally start FS with Wolves and harass the enemy. Blademaster is fun for screwing over humans and night elves and TC is best for taking on undead. Orc is totally up to you.
Also, notice how they harass if they do. If they do it once, its normal. If they doing it twice on the same place, they are either gonna rush or cover something up. Anything more after that, then they are obviously teching.
Start off with GRUNTS no MATTER WHAT YOU ARE GETTING. Starting Trolls is the dumbest idea since massing Infested Terran back in SC. If you do want to get trolls, start collecting them after 5 grunts, so they have 700 HP walls defending them.
If you are planning on Raiders, be sure you get grunts too and a kind of caster. If the enemy is distracted with something like creeping or rushing. You can be lucky and use your siege to destroy some of thier base so they either leave the field or force to tp. If you destroy thier main in this process, you are god if you can escape. In a deadlock battle, net air so they cannot move. If the air is pulled to your raider, the aa player can easily snipe them without fear of them flying off. BE WARNED: Raiders aren't battle-class units, they are ment for harassing or aa if you don't want to get trolls or air.
If you are going to go Tauren, Mix and match 2 kinds of casters. Shaman seem good, but not when the enemy has destroyers. Since they will turn your bloodlust into mana for themselves. I usually do Walkers/Docs, since Walkers dispel and Docs heal mass armies for 2% every second as long as a ward is setup. Set traps on the enemy forces to stun them for 6 seconds. Also, revive any tauren that fall with Ancestral before the corpse is rotted, destroyed, or revived by necros.
If you plan to go on air, start off by getting grunts with the wyverns. Then when you attack, keep the wyverns a fair distance from the grunts. This way, if fiends web them. They have 2 options.
1) FF on the wyverns, but have grunts attacking the fiends
2) FF on the grunts and leave the wyverns to do thier powerful piecring blows.
In this confusion, you can take advantage. Hoping you don't lose your ground or your wyverns aren't killed.
Shaman are required here to make up for thier slow attack speeds, also target melee first with wyverns. If you see things like wyrms or chims, get them first then the melee. Melee can push people back and can possibly reduce your aa to shreds.
Also don't be an idiot and focus fire on heroes. You need to micro and if you don't, you will lose all your men and be blamed for a loss that could have easily been avoided. Only go for heroes if you got a clean shot on them, or if you have a blademaster with an orb and the enemy is distracted with something else.
You can also AIM tps, aiming them will determine exactly where your units land. If you pull it off correctly. You can trap an enemy inside the base and easily kill them off in the crammed battle style. Just watch out if you get sandwiched.
Hero wise, arm all your melee heroes with Orbs so they can strike air, espeically the blademaster with his Critical strikes.
If you need extra help, post back and clarify the topic.