On the how, since "hand wash" covers a lot of technique and the failures are nearly all technique rather than fibre.
What actually felts wool is agitation plus temperature change, not water. So:
- Cool water throughout, and the same temperature for washing and rinsing. A cold rinse after warm water is what shocks the fibres.
- Do not rub, wring or swirl. Press it gently under the water and leave it. Movement is the enemy.
- Lift it out supported, not by one corner. A wet knit is heavy and will stretch out of shape under its own weight.
- Roll in a towel to remove water, then dry flat on another towel, reshaped to its measurements.
For the collar problem on the blouse specifically: you often do not need to wash the whole garment. Spot cleaning the collar and cuffs and airing the rest deals with most of what "not fresh" actually is, and it is far kinder to the fabric than repeated full washes.
General point that saves the most money: most things labelled dry clean need cleaning far less often than people wash comparable items. Airing overnight, brushing, and steaming does the majority of the work for wool and for anything tailored. Cleaning is for actual soiling. Over-cleaning a coat wears it out faster than wearing it does.