My view is that talk of flying a rate of descent is a red herring.
The MOST important aspect is to fly attitudes - set and hold and attitude, trim it, adjust thrust to fly your desired speed and then see what happens.
If you are too high, reduce pitch attitude 1 degree, hold and trim. The adjust power to control speed.
If you are too low, simultaneously apply some power, raise the nose 1 degree, hold and trim.
After making any correction, wait a while to see what happens - if the still not right, make another small correction and then see what happens.
You must hold stable attitudes and then you will be able to make measured corrections to achieve a sensible recovery to the ideal. Many people make corrections that are too big and just shoot through the ideal on their way to an even bigger error in the opposite sense.
Small corrections work for heading, too. Before establishing the ILS, calculate how many degrees of drift you will have and bug that heading. If it does not work, make a small correction - applying bank that matches the change required.
e.g. If 1 degree left of QDM, apply a correction of just 3-4 degrees to right right, using 3-4 degrees of bank. If you over bank, you will shoot through the desired heading before you have a chance to roll out.
I also advise people to over estimate how much drift they have if they are not 100% sure - it is easier to correct from upwind with asmall heading change than from downwind with a large one.