First read the post before this about sorting the laundry.
Items for low temperature need a very kind detergent which rinses out easily.
Dreft, Robijn are OK. Especially in liquid form.
You can drip a bit of it on the dirty spots before throwing the laundry in the machine.
Don't use too much detergent as it might fill the whole machine and cause damage.
Black laundry (and dark blue, dark brown) stays black longer when you use special black liquid detergent.
white laundry for 40 degrees and higher
White laundry for 40 degrees and higher can deal with detergent for white laundry. It contains a bit of bleaching stuff which helps to keep the laundry white.
Be careful with nylon etc. It changes in a dirty looking yellow whitish colour when washed at too high temperatures and with bleaching stuff.
Use detergent for coloured laundry.
The cheap stuff doesn't wash as well and often doesn't prolong the life of your clothes as well as the detergent which costs a bit more.
The smell is also something you want to like.
Softener can replace the smell of your detergent.
It also keeps the clothes a bit smoother, so you don't need to iron them.
It can also work as an anti-static, which is of help with nylon, for instance.
It prolongs the drying when hanging the clothes out to dry.
But when you use a dryer it makes the clothes even softer.
Always keep a piece of this soap near the laundry machine at a fixed place.
You don't need to use it often, but it's quite handy in case of an emergency.
Spots from most food and juices can be dealt with.
It's best to put cold milk on fresh bloodstains, but when they're old, use oxengallsoap and leave it for a few hours.
Rinse it out before throwing the item in the machine.