What are Your Scenery Essentials?

Either the Kurage station scenery pack or the Red Veil's one can give you some buildings tall enough to completely cover most TAGs.

For the DIY part, I tend to craft some barrels using more or less small (about 1''/25mm of base) that I glue together (two to each other so they look solid, then another two on top) is a very inexpensive way to make some fast cover for S2-5 troops (and total cover to S1).

Some "walls" made with cardboard to the height I consider OK soon follow, mostly because aside the cardboard CB scenography, the one I craft I do without those so I can place modularly.
Then, some stairs so the troops can move to heights if needed. Two or three catwalks can also give some extra movement.

If you can find toys on the right scale, then one or two trucks and a bunch of cars can turn a deadly trap of a street into something that can be traversed without being sniper-food.

Finally, the easier pieces I found are the pringles-tube based (chips sold in cardboard tubes) that I cover with some printed textures from Tommygun, and then I apply hot glue to a circle of cardboard on the metallic piece, after which I cover that with some PVA and sand I then paint like a street (vallejo's black + cold grey, then dry brush with white very slightly); I have also made a bunch with some wider, shorter cilinders (from cocoa packs) to make different heights.

 

I personally don't have any lasercut buildings but have about about 3 tables worth of terrain. Mostly because I find lasercut buildings don't store well, and need a set of shelves. I want thing I can put in a box and store. Even with all that this table sees more use than the rest combined. I don't want to sound like I'm repeating myself, but its the best bag for you buck in terms of infinity terrain. Extremely playable, stores easily, My set is about 4 years old and its still holding together. To get the basic buildings built is less than 50$ worth of dollar store craft boxes, a can pf primer and some glue. I attached the file I used for the doors and windows if you want to try. Once you have the core done you'll need to work on the smaller pieces.

If you are looking to make wall sections I would aim to make the walls 3.5 inches long, and somewhere between S6 & S7 height. With a couple corner pieces you can make a quick objective room out of them. I made a box of these as tournament helper boxes, I can easily bring it to a LGS and help stretch the terrain. If you can get your hands on a some Black Masking tape, it covers the edges of the foamcore really well.

 

I literally took the dollar store craft boxes, flipped them upside down. Then flipped the lid and glued them to the bottom of the box. The edges of the lids are just all enough to give cover for an S2 model.

When Painting the boxes I found the craft boxes a little too yellow/tan so I dusted them with white primer to lighten the color a bit. I intentionally left it imperfect to add character. For the windows I printed up a sheet of windows, and glued it to spare boxes, then cut them up and glued them to the outside. It took me a while to find multiple window images that where similar style, but not identical. Again it adds character. having them sticking out a bit really helps the look. Otherwise it's too flat. As for doors, you can't do the same. If you want the boxes to stack you need the door inlaid, otherwise the box lids won't fit. The last step I did was air brush the Burnt Umber to add weathering. It REALLY helps the aesthetic, without it the table looks a little too clean. But its still very playable.

For stairs and bridged I used some wooden cubes to simplify the construction. Its not as pretty as some of the laser cut stuff, but its quick and extremely playable. I also think it makes the terrain stronger. I tried to make some bridges out of the lids of of the 5 inch craft boxes, but there are a little short, and prefer longer bridges. You'll have to go to a craft store and get sheets of cardboard. Unfortunately you can't get the same color as the craft boxes. I used Army painter Bone/Ivory colored primer with a white primer dusting to match the craft box buildings.

 

Besides the walls, the biggest addition to MotoTronica would be some scatter terrain, especially planters or low barriers for infantry to gain low cover from. Remember that the crates in MotoTronica already provide total cover for infantry but only partial for TAGs that they can vault over, and same goes for the buildings which are actually shorter than the S7 template.

This table is mostly home made, the signs are laser cut MDF as are the spires on the roofs, but all the buildings were made from 3mm foamed PVC (same material Plastcraft stuff is made from) cut on a mini tablesaw, but could be cut with a knife and ruler if you had the patience. Windows/doors were made from plasticard cut on my Silhoutte Portrait, but could also be cut by knife and ruler. I specifically made the buildings 70mm tall so that they provide total cover to TAGs and couldn't be vaulted over. Planters are salsa/salad dressing cups from a local restaurant with a disc of foam inserted to bulk out the "dirt", a railroad tree glued down and then sand and flocked like a base. I painted ladders on the sides of the buildings, but the orange ones are made from LEGO ladders with some loops cut from paperclips glued to one end so they hang off the sides. Not pictured, but I also have some longer planters made from 20mm strips of foamed PVC that I made into boxes 25mmx100mm long and hot glued cheap fake aquarium plants into.

The billboards are great because they can go down anywhere you want to break up a sight line. The ones that hang off the side of buildings are extra nice because they provide more height to block LOS and yet can't be stood on, so they don't become sniper perches. You could make your own from cardboard and print out photos or cut out magazine images to glue on them to make your own billboards. You could also print out images onto transparency film like for overhead projectors to make your own clear holo-ads, then cut out a frame from plasticard/cereal box to add rigidity

 

I know its not DIY, but one of the first things I used as Ininfity terrain back in 2011, and ever since in basically every game are those box sets from Dust Tactics;

Those things are basically S2 boxes that can always give a decent waist high to toal cover depending if laying down or standing up or stacking 2 or more.
They also come in 3 different designs, are not super expensive, are prepainted and as a deluxe version you can get some resin senic base to build bigger stacks.

Just search for Dust tactics Ammo Dump (and ignore the super expensive Premium Edition)

only downside is the shipping, but sometimes you can find them quite cheap in stores who try to get rid of DT.