just common sense.
lots of CLEAN mulch 6inch. chips or bark. Disturb the surface annually to kill new seedlings then add a thin layer of new mulch. Dont plant ivy. Use Gin,Vinegar or boiling water to kill stubborn deep rooted weeds.

work from the top down when clearing. a little each day.
You can use filter fabric to block weeds that cant be completely pulled. Costco has this in a big roll. dont use black plastic.

You may want to put in a drip system first while you are at it. No digging necessary. It should just be buried in the mulch. Depends on what you want growing there.

I found the major difficulty always seems to be seeds from outside the area depositing on top of your work. Either by wind,water or birds. In severe case every 2-4 years remove and replace a 1-inch layer of mulch.

If you have a very steep slope evaluate your erosion control. Water is controlled by swales, trees, divert runoff from uphill non-permiable areas around the slope.

If its a typical gentle sloping front yard then plant some native ground cover and properly sized ornimentals. Depends on you area.
If its a shaded woodland then add more shade. Your weeds and grass are probably taking advantage of the avilable sun.
My favorites for WA groundcovers good on slopes are kanick-kanick and lithosprum(sp-blue flowering stuff) Its very impressive and will flower for a very long season if watered with drip). Also ice plant for sunny location (vivid pink flowers and indestructable through freeeze and blow torch - not considered invasive in WA). All can grow by transplanting cuttings by the way.

Last but not least. Look at similar solutions nearby and ask the owners. When they trim groundcover is also a good time to start cuttings. So ask.

Here is a link that might be useful: My sloped rear yard

Hi gang, Marion here, Im new to this forum and would like to ask hydrogenie if Gin, vinegar, or boiling water will kill Ivy..my ivy roots have turned into tree branches, pls help

What a beautiful job you've done on landscaping that steep slope! What does the rest of your property look like? I bet your neighbors are envious, or do they have the same challenges of their property?