I do a simple (and fast) desk for my wife with galvanized steel pipe and carpentry wood.
Step 1: Glue the Top of the Desk
For first I glue all table of the top.
Step 2: Add a Reinforcement
I glue an additional table all around the top.
Step 3: Glue Border
To have a beautiful border effect I glue all around the edge of the top a frame.
First, for a good connect I cut with hand circular saw (and a guide to go straigt) all the border of the top (I remove 2/3mm of wood).
Then sanding all.
Step 4: Add Legs Support
I glued a block of wood with hole where to insert a legs (without use of glue).
Step 5: Base of the Legs
I add a wood base to the edge of legs.
Step 6: Legs (from Comment Request).
I don't know if exist on your country, but I find quite good price from LeroyMerlin (near my home).
3/4" of diameter is sufficient (and cheap) but 1" is more beautiful on 1,70m*0,72m desk. And 1m of 1" pipe about 7€.
You need this elements for 1,70m*0,72m desk:
9 * 50cm 1" pipe = 3,27€ * 9 = 29,43€
6 * 10cm 1"pipe= 0,78€ * 6 = 4,68€
2 * 1" coupling = 1,07€ * 2 = 2,14€
3 * 1" T (TEE) = 1,77€ * 3 = 5,31€
1 * 1" Cross = 3,65€ * 1 = 3,65€
The total cost is 45,21€.
And you need to cut the back legs.
Step 7: Mount Legs
Screw legs and insert in the hole.
Step 8: We Need Electricity
I use hole in the legs to pass wire.
Step 9: The Result
My wife is quite satisfied. ;)
Step 10: An Addition
At the end I do an addition for my wife.