From scratch just using a piece of wood and four cardboard tubes

what you will need:

4 cardboard tubes (can be easily replaced with four wood pillars)

1 piece of wood for the top

Jigsaw

Wood Glue

Ruler and Pen

Sanding Paper

Paint of your choice

one quick word regarding the tubes. I get mine from the trash (they are the inside of packaging foils and companys just throw them out once the foil is empty.) Alternatively you can use the cardboard tubes you get when ordering posters, or a wood piece in the same shape. my tipp would be asking at your local hardware store, they might have something that works in the trash

you can make the top any shape you like. If you like a wiggle look go for that or waves, I wanted to go a little down the arched route and just rounded the corners.

i had a lap shade wich was the exact same size so I used that as a guide, you ca use anything round, a plate a bowl...what ever makes the arch you like

once I've cut out the one side I used the cutting as a template for the other side, this way the arch is absolutely identical

sand the raw edges after you've cut the wood into the shape you've decided on

next take your legs and try out different positions to get a feel for how its gonna look in the end

I went with 15 cm from the sides in and two centimetres space in-between the front and back leg

to get both sides even measure your space from the side (15 cm in my case) and draw a line.

mark the middle of the line to measure the spacing between the legs from there (2 cm in my case)

once that's done the only thing left to do is glueing the legs on with wood glue.

alternatively you can drill holes through the top and screw into the legs and fill the holes with wood filler

since my tubes had a decent thickness and therefor a good amount to cover in glue I just went with glueing them on.

put something heavy on top until dry

last step is paint. I would suggest if you use cardboard tubes to not use water based paint, some tubes get a little wrinkled when painted with water based paint. paints like acrylic or wall paint work just fine. I had mine wrinkle a bit since I used water based paint but once dry for 24 hours the wrinkles were gone, so maybe that's just a temporary thing and sets while drying.