By their very name, borders tend to go down the sides or along the front of the house but, with a long front garden, you could consider putting some island beds in the middle (if you have enough width). A restricting factor on this may be leaving enough width for people/cars etc getting up to the front of the house.
Also putting the beds so that they go across the direction of the slope, rather than down it, should help prevent, or at least slow down, any potential soil erosion.
e.g. if the slope runs N-S, align the beds E-W.
If the slope is too steep you may want to consider terracing, but that then involves a lot more work and /or cost.

Boarders all go in the back bedroom! lol
The other borders stay in the front garden.