the cleaning of inside windows can obviously be carried out in a number of ways, but generally you do them exactly the same as you would with outside windows.
One thing you should do is to make sure you have your applicator (if using a squeegee) a lot drier than you would for outside work, (less mopping up and detailing).
With whatever detergent you use, but in particular any brand of washing up liquid, DON'T USE TOO MUCH!
With washing up liquids and ALL other detergents, a film is left behind on the glass, you will not (in most cases) be able to see it or feel it, but it is there nonetheless and with windows where condensation is a big problem it can make getting a decent finish a problem.
Staying with applicator and squeegee and windows that condensate as you are cleaning them; It really does come down to your technique with the squeegee, but it can help if you use your scrim or microfibre, after having gone over the glass with your applicator, to 'edge' the top and sides of the glass before using your squeegee. This also cuts down on detailing afterwards.
If you have smears or 'kicks' from the squeegee then your squeegeeing technique is at fault.
To help cut down on condensation, try to open as much of the actual window you are cleaning, the through draft from the open window greatly reduces condensation.
But even if you cannot eliminate the condensation, once you have squeegee'd the glass clean, don't worry about any condensation that occurs, once you move away from the window, the condensation will quickly disappear, marks will only be there if you have farted around with a scrim trying to dry the glass :
If you are using a sprayer and buffing clean with either a scrim or microfibre cloth then condensation can be a real pain, particularly on georgian windows. If condensation a big problem and can't be avoided by opening windows, then I use a squeegee (cut down) even on the smallest of panes, but the technique has to be very differrent, you simply will not do a good job squeegeeing off the glass in the same manner as you would on a large pane.
The only reason I would not use Mr Muscle is the cost! Tesco's own brand is the equal of Mr Muscle and half the price (literally)
Another even cheaper option, and one that can also be used to spray on the inside of windows and squeegee'd off afterwards, is Car Plan windscreen solution. At £2.50 for 5l of concentrate (Sommerfield stores) it is a real bargain as you dilute it down at least 15:1
GG3 and GG4, Unger liquid and no doubt other specialist detergents aimed specifically at us window cleaners can also be used in the same way with sprayers. Every one of them work out way cheaper than Mr Muscle too!
Ian