(f) Play some reverse angles.
Everybody hates this shot being played against them but plays hardly any themselves. Every time you play one, it creates real doubt for the next 10 times that you don't and thus has your opponent leaning that little more forward than they would do if you had not played a reverse angle.
Thus, as you get better tactically, you will begin to get to the Holy Grail: you will be able to hit 5 or 6 different shots (played from the same technically correct square position) without your opponent being able to tell which one you are going to play. You are becoming a squash player.
Stop brainless routines, i.e. you boast, I drive. Every routine needs a basis but there must be options, like in a real game.
So, with boast/drive for example, when at the back play mostly boasts but some straight drops and even straight drives back to yourself. When at the front, play mostly straight drives but also some cross-court drives or lobs or drops (which you then play back deep).
Any practise routine can be varied slightly in this way to make it more realistic and useful. Quality not quantity. Brainless "one shot only" routines reinforce bad habits. You will also become predictable, one-dimensional and play shots from positions that you should not do - eg play a boast off a ball that is too tight to boast well.
(h) If your last shot is a good one, your next one will be easy.
If your last shot is weak, you will have to work. Every shot counts. Thus, if your opponent hits a clean winner, you should not be thinking "I must get fitter and faster". You should be thinking "If I had played a better shot before, he could not have played that winner. I will not give him such an easy one again".
(i) Don't fall for the sucker shot.
However bad a position, there is almost always a way out, and with interest. For example, and most commonly, if your opponent plays a good boast and you are being forced into playing a cross-court, then don't play the cross-court. The easy option might be cross-court (which your opponent of course knows) so if you actually play that shot you will merely go from 70/30 down to 90/10 down and with the end inevitable.
A good player knows that his opponent knows that he is being forced into the cross-court so he will actually play anything but that - probably a straight drive or perhaps a drop or (a great counter attack under pressure) a cross-court lob. Indeed, the master player will reinforce the opponent's belief that he is going to play the naive cross-court by totally showing the cross-court (his body being in a position where the ball is very much in front of the body thus "confirming" the shot) but actually playing something else. Hence, he has got out of trouble with interest.
(j) If you are being forced to play a boast at the back, don't.
Of course, there are times when it is the only shot left (but even then it can be played slowly so as to finish at least fairly tight on the side wall rather than very loose in the middle) but it is possible to straighten many more deep balls than you think.
The trick is to shorten your grip if you see that the ball is going to be difficult in the back corner. Move down the grip so that you are holding the racket with your hand half on the top of the grip and half on the shaft. You are therefore now effectively playing with a racket that is shorter than standard and which can therefore get closer to the back wall without hitting it.
With practice, it is amazing how a "difficult" deep ball can actually be straightened and again you can therefore turn defence into attack very quickly. There is nothing so demoralising for an opponent who thinks they have forced you into a weak defensive boast when you actually manage to play it deep.