You are asking quite a broad question so I'll just throw in some random ideas since the topic is so broad you'll need to specify exactly what you have problems with and ask about it... and then iterate and ask again since it would be a long process.
1) Mount infrastructure systems like UPS and AC in advance and let them dry run so you can test if they behave properly f.e. ACs dont produce fog (I've dealt with such problem and it required changes from vendor) UPSs produce weird vibrations and so on. Just put the basic stuff to work as soon as possible so it you can overcome any gotchas it may cause.
2) Plan for expansion in advance - make proper room for additional AC and UPS units. Wire it accordingly. Put exhaust tunnels and everything needed just don't put the unit itself - this will make it much easier for you to expand if needed as you'll have all the work done already. Also add all racks you'll probably need later and wire them. Just don't use them - leave as spare. Racks and wires are cheap - labour is not cheap and it consumes time when needed.
3) Put additional canals (just empty space) below AC units as they can leak fluid.
4) Invest into cable management system so you can label each end of each cable with barcode and have a database of this configuration so you can scan every end of every cable and lookup what is its function where and to what it is connected etc. Don't bother with manually labeling each cable since it is tedious and probably will change in time. Just use generic barcodes attached to ends of wires. MAINTAIN this database as it is the most important stuff. Every single change must be noted in database. Peroid. No exeptions. Also don't bother with color coding the cables - usualy you will end with a mess unless you have a simple network.
5) Invest in security system like webcams on entry doors, RFID IDs and so on. It is not as expensive and will give you audited information on who, when had physical access to the facility. Be strict and anal implementing this - in case of non compilance f.e. somebody is trying to get unauthorized access just raise the alarm to local security staff. It is better to have false positives here.