Don't forget to water - especially new plants, the greenhouse and anything in a pot.
If your garden is looking wild and unkempt one of the simplest things to do is mow the lawn regularly. It has an instant impact on how your garden looks, the smell is fabulous and you will feel great to achieve such an instant result for such relatively little effort.
If you have a large garden and are short of time, why not leave areas further from the house unmown this provides superb food and shelter for wildlife and if you're lucky you will find wildflowers like orchids in your unmown turf. (Once flowering has finished leave the wildflowers to set and drop seed then the whole area could be strimmed and mown.)