Most gardeners grow (or attempt to grow) tomatoes as they are such a good staple food that can be used in so many different ways, as well as looking great!
The seasons have been all over the place, (we had a hailstorm yesterday), making it hard to know exactly when to plant tomatoes. But the time is certainly coming up, so if you are about to get started consider how you want to support them as they grow. Supporting them will improve the look and create a healthy, fruitful crop.
As the plant grows you can secure them with soft ties to the legs of the garden frames (or to stakes if you are using the old-fashioned method), to provide stability and prevent sprawling. Two to three leaders per leg should be fine and remove sideshoots as they appear.
And / or you can drop a stringline down from the top of a frame and weave the leaders up that as they grow to the very top. This is neat and tidy and does not take up much space.
Or try running a stringline through the holes in the legs and all around the frame to create a support that you can espalier the tomatoes along. This is a very effectual use of the space but does require some pruning and shaping work throughout the season.
Once you have decided how you will support and grow the tomatoes, consider deep planting the seedlings as that will enhance the plants stability and promote a stronger root system, as it will send out roots all along the stem (adventitious roots), allowing it to take in more nutrients. Deep planting will also be good for the plant's health, as you will create a barrier against soil borne diseases and allow the plant to reach deeper moister.
Now you ready for the season (if it ever arrives), when there will be more work to do with them, but I will talk more about that as it progresses.