A couple of pet peeves
Whenever at all possible URD should be loop feeds and on the same phase and same circuit. What is the purpose of having a loop feed that you cannot tie. Also do not put both ends of the loop on the same pole as it makes pole changeouts a real pain and more time consuming. Riser poles should be riser poles only when possible. You should try to refrain from having a 3 phase riser on the same pole as a OH transformer or other pole mounted equipment. Ensure there is an adequate labeling and marking system, number transformers sequentiually. Mark elbows with the station number they are going to (if you are at station 4 then one elbow would be marked 3 and one marked 5). Use fault indicators with the fiber optic eyes so the crews do not have to open the tx to see if the indicator is flashing. Avoid "T" splices and elbow fuses at all costs. Install everything in conduit, it is much quicker to yank bad cable out and replace with new cable than to locate, dig up, and repair a faulted cable.
DO NOT INSTALL SUBMERSIBLE SWITCHES IN MANHOLES, HELL FOR THAT MATTER DO NOT INSTALL MANHOLES AT ALL UNLESS ABSOLUTELY NEEDED AND DANG SURE DO NOT LOCATE MANHOLES IN THE STREET, IN STREET SIDE PARKING AREAS, OR IN AREAS THAT LIKELY TO BECOME EITHER.
Always provide a means for grounding cables when using 600/900 amp connections. These should be easy to use and not require disassembly prior to testing and grounded.
LABEL LABEL LABEL VERIFY VERIFY VERIFY everything, then triple check those labels. In 25 years the installers will not be any where to be found and someone will be troubleshooting, switching, replacing things and the only things they will have to go by is the labeling used during installation.
Good luck, every system is different. Find the linemen working on the systems you will be designing and ask them what they want to see and how you can make their work easier, safer, and then make the system work for them.
Take only what you earn, give only what you can, learn to respect yourself before you can expect to respect anything or anyone else.