This area can work out from a few hundred Euros to many thousands. Landscaping is down to your individual preference. You can either take it on yourself or you can pay for a landscape gardener to do everything for you and if you can afford it this is the route to take. Remember, a well landscaped garden will add value to your property.
Before you start you need to set a budget or else it can get really out of hand. You must analyze your soil ( you can buy small kits to do this with from the garden centre ) this is to make sure you are putting the right types of plant into the ground. Check the position of the house and how the shade and sun affect the areas of the garden during the day. If you have neighbours look at what plants grow well in their gardens. Look at what wild plants are growing in your area as very often other varieties can be bought from a local garden centre. The bottom line is that it is a waste of time and money to plant a beautiful garden which is going to be dead in six months because the plants are not suitable for your soil.
Once you know what plants will grow in your area start drawing up your plans. Remember to think in the long term when planting and give each plant room to grow. If you are hiring people with machinery get the job priced and make sure you are both clear on what the job initials so that all areas are covered within the cost. You could always hire mini diggers and cultivator yourself but from experience it usually works out cheaper, quicker and with better results to pay someone else to do these sorts of jobs.
When you are at the planning stage of your garden be practical and think about what you want from this area. An example of this is to build a Barbecue next to your seating area so that the cook is not away at the other side of the garden. Then if children need to be supervised why not put their play area within viewing distance of the seating area so that while the adults can carry on talking, the kids can play in safety and be within sights.
If you are planning a water feature the size should be considered carefully and again if small children or animals are in the house you must think about their safety by perhaps putting a thin wire mesh over the water to prevent drowning.
Look at what is already on your land, there might be a tree or some bushes that are well established but are in the way. if you do not wish to loose them get advise from professionals and see if it is possible to relocate them and when the best time of the year would be to do this.
Have you thought about a small or large vegetable plot, fruit trees, green house. Think about if a lawn is it what you want or will it be too high maintenance. Is your garden going to be an extension of your house or is it going to be an almost self maintaining view from your window.
There are so many things to consider, so make sure that you and all members of your family are happy with the final design before you start.