My wife and I have used coconut liners for years, and I have used the coconut pressed coconut cups to plant seeds in. See below! They offer great drainage and plenty of air for the roots, no nothing special just put the coir (coconut) in the planter add your dirt and plant! It's that simple. The only suggestion I have is to check moisture more than you usually would, as water will drain through and make sure it does not hang over items and guests you wish to keep dry! Hang in area of your patio where it can drain freely like maybe over another planter that sits just below using the drain off to water the plant just below! You can also buy a water well that will help you keep the coir moist fo about one month! I start my garden seeds in the coconut cups and when plant is big enough plant outside the green house cup and all!
I like to add some water grabber (the crystals you mix with soil which expand greatly to hold water). You can just fill in the top and use trailing plants around the edges but you can also cut slices in the matting and insert plants through the sides or bottom. (An old steak knife works great for this). This is particularly effective when the basket can be viewed from underneath. My baskets are fairly low so I like to put something a little upright in the center (I love dianthus for this) and then something trailing on the outer rim (white petunias and trailing white verbena works well for me). I would love to use more lobelia but it fries too quickly in Georgia sun... looks so nice in Vancouver though! If you live in a warm area, think about your color combination. The reds and oranges look greater together but can make an area "seem" hotter where the cooler whites, blues and greens don't. There are loads of combinations you can do, every garden magazine has pictures, just make sure ...