Analysis first, then plan, as Tookoo recommends. Use native plants, as neotoma recommends. Get specific plant recommendations locally, as Terri & sgelade recommend. Here is my two cents worth, for the shortterm. a. Remove and stockpile the lawn edging and most of the mulch back against the fences. b. Take a can of spray paint, or a bundle of surveyor's flag, and mark the largest circular or curved form that will fit within the fenced areas, no matter where the trees stand (inside or outside of the line) to form the temporary edge of your lawn area. See if the entire family agrees on the alignment or just do what looks best to you as the Senior Gardener. c. Add the wood edging to the new edge, or, it will look a lot better if the edge is not visible, using a steel edge whose top edge is down just above the grass roots and no longer visible, and not an impediment to the lawn mower. (when you form the plant beds, you will dig down a couple inches at the edge, where it meets the steel, and then slope the bed up from there, and the mulch will be contained at the level of the lawn, beyond) My recommendation, after you call in your landscape advisor, is to fill the beds totally with ground cover, beneath the shrubs, so no mulch will be seen after the two years of plant growth, using only a finer textured mulch which will become part of the soil bed. (Maybe the bark mulch will smell good in your new fire pit, along with the wood edging.) d. Plant the entire area with grass seed or sod and enjoy the beauty. The curved edge will make the space appear and feel larger and will decrease the maintenance of the smaller bed areas. On the subject of tree placement: analyse first, then plan. Look at all the views beyond your fenceline from all windows of the house, the living/ dining areas, all the bedrooms, to enhance the good views and to block the big, the bad, and the ugly. The large trees on your list will block views from the upper windows, The small horizontally branched trees will be a piece of sculpture in your downstairs view throughout the year, while their flowering and fragrance yet another reason to be alive. For instance, if you have an attractive small tree that has attractive flowers and foliage, PLUS has attractive bark color and has a sculptural quality in the off-season, you won't have to visit the museum quite as often, with a sculpture garden right out your window.

Love this style never dates, trees can get to be a problem if too close to the home but there are products out there such as gutter guard products that fit seamlessly in your guttering.

Hi Evan, it is certainly doable. My back yard is probably 5 times as big as yours. I had a deck put on out the back, built all the garden beds myself, edged different sections of the garden myself, and topsoiled and laid the turf around the new deck and along the side of the house myself. I even made my outdoor furniture. I also filled all the garden beds with soil and planted them out. I got truck loads of top soil and mushroom compost delivered and wheelbarrowed it from the front to the back yard. If you are able to do stuff yourself, it isn’t that hard (I was in my forties when I did all this). You do need a concept plan of how you want your back yard to look. Check out pinterest for ideas. Some small trees (crepe myrtle for shade in summer and flowers would look nice). Think how you want to use the back yard. Hiding the fence would be good. Painting it a dark colour like someone suggested wouldn’t hurt and would add a lovely contrast to greenery. I made some decorative hangings to cover my colourbond fence while the vegetation grew. A water feature would look nice too. You could create an oasis there with a bit of hard work if you can’t afford to pay someone to do the work.

There are some truly beautiful natives on the scene now. I love acacia cognata for it's lovely mounding habit and the fact it fits into nearly any style of garden. It looks lush and temperate but also flowers. Davidson plum is a native that takes up very little space but drops kilo's of fruit after a few years. If you like tart jam like rosella, and cranberry then davidson plum makes a beautiful tart jam and also a lovely steak sauce. It's very simple to grow and a distinctive looking tree. Also makes an excellent cordial. Dianella is a native strap plant that clumps and looks stunning in the variegated leaf. It's cheap and easy to find and in mass plantings looks the business. and while a coffee tree is not a native few other trees are as easy to grow and beautiful as this one. It grows to below 3 meters in a lovely dense bush shape. The leaves are deep green and glossy and it flowers with hundreds of delicate white blooms that smell like jasmine. It does not need pruning and looks good for absolutely years. If you want a lush look to your garden you can't go past a $7 K12 coffee tree that will fill a gap and look amazing. We put ours in as seedlings about 7 years ago and they are mature now. Both are beautiful shaped trees that have never been pruned and need zero maintenance or watering. They are fabulous ornamental trees that produce about 5kgs per tree of coffee beans a year. A truly worthy screening plant when you want a lush backdrop and maximum privacy. And for a waterfall effect over terraces like no other you can't go past dichondra silver falls. It's native.