For you must either use plenty, or leave it alone.

A ragged ribbon-border can have no admirers.
If time and money are both lacking, and horticulture is not a hobby, divide what sum you are prepared to spend on your little garden in two.

Lay out half in making good soil, and spend the rest on a limited range of hardy plants.

If mother earth is well fed, and if you have got her _deep down_, and not a surface layer of half a foot on a substratum of builder's rubbish, she will take care of every plant you commit to her hold.

I should give up the back of the borders (if the aspect is east or south) to a few very good "perpetual" roses to cut from; dwarfs, not standards; and for the line of colour in front it will be no great trouble to arrange roughly to have red, white, blue, and yellow alternately.
One of the best cheap bedders is Pink Catchfly (_Silene pendula_).