Im an undead player, Karanadon on the lordaereon realm, and my advice that follows is gathered from experience from replays, my own games, forums as well as matches I spectate online.
Basically the current popular human strat right now is mass riflemen. Riflemen are the strongest tier one unit with the exception of ghouls at tier three with the ghoul frenzy upgrade. Basically, 2 barracks are needed and from each one create riflemen. Not too hard. Talking in terms of heroes, I recommend the arch mage with the blizzard/elemental skill build since blizzard works horrifically well with riflemen. Get an arcane sanctum at tier 2 and start training priests, and knights at tier 3. It’s a simple strategy that will win half of the time correctly and like the undead mass fiend, or the NE mass huntress strategy, it really is just the first step into improving your playstyle and most importantly your micro. I strongly recommend that if you haven’t been playing long, you should get used to this strat as this is basically practice for other strats and such. Trust me, all good players will have used this method of practicing once and I used the mass fiend build to help improve my micro as well as get better in the game.
In terms of interesting builds, try tavern heroes. Try the panda/riflemen/knight combo with drunken haze and breath of fire as they seem to seychronise really well together. The gorgon (with arrows/chain) combo with footmen is, what I think the BEST human rush for early game, and can devastate opponents in the first 15 minutes because of gorgy’s prowess in the early game (Trust my word, I have been beaten countless times by humans using gorgon rush). Footies back gorgon up so well and I find this build really effective. Its really like the orc far seer rush, its really devastating and has the enemy on the backfoot really fast because of the early game strength of this combo.
In terms of trying human heroes other than the archmage, I really recommend mountain king solo with footies/sorceress but this becomes more of a glass dagger type of strat. Bloodmage isn’t really popular and I rarely see it being used effectively and pally is more of a hero used commonly in reign of chaos but not as good in tft. Archmage and Mountain king are the way to go.
Ok, countering. This, I believe is the soul of wc. Countering is basically what players are doing in higher level play, if you watch replays or matches of a higher level. I have problems with the blademaster as well. When I play him with undead I chain nuke him with death coil/nova combo and I get dreadlord to sleep him as my nukes cooldown. I really think this is similar to a mountain king/bloodmage combo. Nuke that little blademaster’s *** and keep a DUST OF APPEARANCE on your heroes at all times. If he wind walks, use dust, ethereal him and nuke him to infinity and beyond. Mirror image really is a shifty skill that I despise and ww blademasters are not the main problem for most players, it’s the crit/image ones that force you to take massive dmg. Images are annoying, but they don’t do damage. Focus on his units and use your spells (flame pillar, thunderclap, blizzard, etc.) to try and force him back, and remember to move back if he gets a lot of crits and your men are dying =[. If your getting harassed by a ww blademaster, just get an arcane tower. Easy.
Counter air units with riflemen and bigger air units (Frosties, chimeras, wyverns) with dragonhawk riders. Counter melee units with riflemen. Counter casters with spellbreakers (duh). Counter summons (necromancers) with priests. Counter ranged units, especially NE with sorceress. Counter NE with piercing damage, as Ne have a lot of unarmoured units. Counter Orcs with riflemen as grunts will fall really quickly to focus fire and spear throwers are weak. Counter Undead with footmen/sorcerress as well as blizzard or flame pillar, basically AOE stuff that rips through ghouls and scores free hits on buried fiends. Ina mirror match, counter specifically the unit they use. Most likely it will end up as a mass riflemen/knight/priest combo.
Hope this helps, either pm me ingame or email me for more help. =]