Just like real sex is never the same as porn sex (they never seem to get elbows in the way or miss the hole or get the wrong hole or spend 10 minutes recovering the condoms that have fallen down the back of the bedboard in porn sex... ) real bondage is never the same as porn bondage.

The trick is good planning. If you are being spontaneous then you are going to lose out on this. You could, however, also argue that in planning you lose out on some of the tension of spontaneity. However, you can get over that by planning in a very ritualised manner - telling the sub to go and 'prepare themselves' (tying hair back, getting dressed/undressed, making sure they have itched all the places they think may need itching, making sure sexual organs are clean etc) while the Dom/me prepares all the equipment for bondage.

But there are always going to be unforseen circumstances... you just have to accept them and live with it.