You spend a lot of time making your garden look attractive. You make sure you have just the right flowers, in size and colour, so that everything blends in and looks good together. There may be some ugly elements in your garden that you can't eliminate, such as sewer access, concrete slabs or chain-link fencing, among other things. You can find ways to cover up these items and actually make them look like a part of your garden.
Cover up a septic tank's concrete slab by using it as a base for more concrete. Set a birdbath on top of the slab to partially hide it, but also make it look like you want it there. Place the birdbath on top of the concrete slab without fastening it down to allow for easy removal if you do need to access your sewer or septic tank.
Use large potted plants to cover up concrete slabs or even unmovable concrete pillars. Set the potted plants on top of the concrete slab or pillar to give your garden an added dimension in height. Use cascading plants in your pots, so the trailing vines will further cover up the concrete pillar.
Measure around the thing you want to hide and plan to make a four-walled trellis structure. Cut four pieces of lattice to the measurements you need, attach them together at the corner using hinges, screws and a screwdriver. Leave one corner of the lattice wall unhinged if you do need to gain access from time to time.
Cover up a tall ugly thing in your garden by building a tepee out of three wooden stakes. Gather the stakes together 5 inches from the top and wrap some rope tightly around them, weaving the rope in and out to make it secure. Place the tepee over top of whatever it is you want to hide and plant a fast-growing vine to climb up the tepee and hide the ugliness.
Plant some hedges to cover up any unsightly objects you want to hide, such as air conditioning units. Choose hedges that are as tall or as short as you need them to just cover up the unit.
Think about the area you want to cover before you cover it. Air conditioning or central air units may need attention every once in a while as well as septic tank access. For these spaces, choose an idea you can easily remove, or will not feel bad about cutting back should a repairman need to come. You can also choose plain old picket fencing to cover up ugly things in your garden. Cut the fencing panels to the widths you need and put them up. Picket fencing will not detract from your garden as other types of fencing might.