Thought I would just share my tips on team talks and in-game shouts or whatever they are called.
As with Fm15 squad morale is extremely important. When people usually try a tactic, and experience a lot of success but then all of a sudden have a very strong dip in form, they usually say stuff like "the AI figured it out" or "stops working after half a season, **** tactic". This is very rarely the case (SI has even stated that the AI doesnt 'learn' tactics). This is usually because you have one match where you don't win, you then get a slight drop in morale and treat it poorly.
How i do my team talks:
I aim to have everyone green both at the start of the match and at half time but never with the "Looks delighted" reaction. Before a match I either say 'Assertive': "I expect a win" or "keep up the good work bla bla" if my assistant suggests it. This will usually give a few of the players "Looking Motivated" which is the best reaction in my experience. Then, on the players who have not reacted, I say 'Assertive': "Have faith". This will either give them "Looks Happy", "Looking Motivated" or "Gained Confidence". This usually leaves me with around 8/11 in green. For the duration of the game
Half time:
At half time the team talks depend on the current score of course. If behind or drawing i always say 'Assertive': "Expect more" and then say 'Assertive':"Have faith" to all players individually (you can use the 'Defenders', 'Midfielders' and 'Attackers' drop-down menu for this. If am ahead by 1-2 goals i say 'Assertive': "Dont get complacent" and use 'Assertive': "Have faith" to the players who either don't react or have a 'red' reaction. This usually leaves everyone green. If i am ahead by 3+ goals, i use 'Cautious': "Say nothing" and then use the drop-downs to say 'Assertive': "Have faith" to every player.
During the match:
During the match i use the 'Calm': "Encourage" at every time possible. This really, really helps.
Post Match:
After the match is a lot simpler. If i win, i just say 'Calm': "good win" or whatever. If I draw or loose away I either use the "Unlucky" or the "Dissappointed" depending on the opponent and how many chances you create. It is very important to get a feel for this difference as a "Dissapointed" team talk after a draw against Man City away, can destroy your squad morale.
Hope this helps.
Edit: Also, never ever ever do team meetings because you feel you are playing well or not so well. It only gives a positive response like 1/10 times and if you get a negative response, it's usually really really bad. This is just my experience though.