Here are a few tips on playing the game that have helped me; firstly there's a section on playing without cheating, then there are a few extra tips to use in conjunction with the cheat module.
GENERAL PLAYING TIPS
>To start:
Build a windtrap. Then build a refinery, otherwise when you activate the cheat and it decides to go into freefall, it will stick at 1005 rather than going to zero which is inconvenient (but not a problem if you keep your fingers on the cheat keys constantly). Build a radar station to see where you are. Use whatever vehicles (troops are slow, and can't see much) you can spare to explore the local surroundings and make your map more complete. Look first for spice, then you can find the enemy - it might be a good idea to backtrack along the enemy's path to his base so you can see when he is approaching (although you will probably lose the vehicle). Try not to leave little gaps as the enemy can disappear in these.
>Further in:
Find where you enemy is based. I send expendable vehicles (i.e. not the good stuff like tanks or launchers) to the corners of the map, then get them follow the edge of the map. If you don't find the base immediately you can move them in a little and keep going round the edges in ever decreasing squares. Going round the edges means that you will find the back of the base, which means you don't have to run the guantlet of the enemy's entire defences when you attack.
Buildings - if it's not a factory, a repair centre or a star port, build it near the centre of your rock island. It's better to have your factories etc. near the edges so that when a vehicle is disgorged it will be placed in a convenient position (not trapped in the middle, or placed in some ridulous place by a carryall).
If you're in a rush or just can't be bothered to create all those little concrete tiles, simply dump buildings on bare rock. As long as they are up against another building or some concrete then they will go down, although you will have to repair them. Handy when a Harkonnen missile blows up your entire power system in one go and you need that radar up again as fast as possible.
Repair windtraps whenever possible - it's damned inconvenient when the radar goes down due to lack of power. Also whenever possible build your wind traps all bunched together. This way when you have to repair them you aren't hunting all over for them.
Don't bother to fight infantry units - just roll over them with a tank, harvester or other heavy vehicle.
Don't just send one or two vehicles towards the enemy's base. Stockpile your weapons in a safe, out-of-the-way place (preferably on rock in case of sandworm activity), and send a huge attack force in at one go. You'll be more likely to get enough through the defences this way.
When you have launchers, these are very good at getting rid of buidlings but lousy at close combat, so stick a couple of (seige) tanks nearby to take out any enemy vehicles.
Attack the enemy's construction yards first, it should stop them rebuilding any other buildings you destroy (but beware - they may have TWO construction yards!).
Don't get too close to enemy turrets - take them out from long range with your launchers. Rather than moving them forward first then attacking which might put you in the firing line, put your launcher in a safe position then tell it to attack the turret. This way the launcher will move only as far forward as it has to, and hopefully this will be a safe distance (although not from all angles).
Note that launchers have an especially long firing range, and so consequently when you place them in a patch of uncharted territory they will reveal much more of the map; this applies to other vehicles in that the smaller the firing range of the unit, the less it will reveal of the map.
Don't put Atreides sonic tanks in a position where, when they fire at the enemy, they will be firing across your own vehicles or buidlings, because they will do the same damage to your forces! Also, move rocket launchers to a safe distance away from your base so they don't blow up your buildings should an enemy vehicle approach.
>When you can see which direction the enemy is approaching from:
>>Before you can build turrets:
Place a line of vehicles (preferably tanks) to block the path of the enemy. This means the enemy will have to either slug it out with half a dozen or more of your guys, or try to get around (hence a line - the longer the line, the harder it is to get around, like a wall in football). Make sure you replace vehicles that start smoking. Make sure you have a few to keep round the back of your base, just in case the enemy flies a few troops in...
>>When you can build turrets:
Again, simply put a load of turrets (preferably rocket turrets) along the edge of your base facing where the enemy is coming from. Enough rocket turrets and the enemy will be blown away long before they get anywhere near your precious heavy factory or whatever. Don't forget a couple round the back in case of sneak attacks.
>Fun thing
When you can build turrets and you have access to an MCV you might want to deploy a new construction yard closer to the enemy - this way they get nowhere near your base. You can also build concrete paths leading right to your enemy's base if you deploy on the same rock formation, which means you can build your turrets in a position where they will take out enemy vehicles right out of a factory! Enemy turrets will not attack your turrets, although of course enemy vehicles will - so put about three or four in a cluster. Don't forget you'll need extra power, but your windtraps can be built right back at you original base. Using turrets to blow up vehicles inside an enemy base means that enemy concrete tiles are destroyed, so you can eventually build a path right into the heart of the enemy base and take out everything that moves from within (try it on the demo version - very easy)!
TIPS ON PLAYING WITH THE CHEAT
You can now stop all that harvesting nonsense and use the harvester to go on scouting trips to reveal more of the map - it's a good vehicle because it's got a decent amount of amour, and should it get blown up a new one will be provided free of charge.
When you get to the later levels which restrict how many buildings you can have, you can build less silos. A dangerous but useful feature is on the last level, where you can only have 20 structures - build everything you want, then blow up your own spice refinery. You should be able to build another rocket turret, but note that if you get some buidlings wiped out by a missile etc. then you will not be able to re-build them without first re-building the refinery.
Build a starport, go into it, press the cheat and then order all you want (i.e. with 9999 credits you should be able to clean the place out). Then you can blow it up to save space and power.
