A few useful tips:
1) in a box with oxygen tank and mask there is enough espace to add extra items. Good idea would be (depending on your race): splints and medications, welder and wires if you are an ipc, crowbar for power outage events. You can get very creative with it.
2) style is everything. If you are a generic looking officer with mask and helmet on green alert level, people outside of sec will less likely cooperate with you.
3) dont assume that after a couple of rounds you are a machine of justice, unstoppable and invincible. If you walk around maintenance alone looking for trouble, believe me, you will find it. A lot of people can kill you in a matter of seconds and nobody will even notice you dissapeared from crew monitor. Dont patrols dangerous places like maint with known vampires and lings or posdible cult base alone. Pair up eith another officer or two, security cyborg is even better option.
4) oh right, always set suit sensors to maximum! You can do it by rightclicking on your jumpsuit and selecting the sensor option. Even if criminals and punks can now locate you, it means nothing compared to whole security team and cyborgs being able to locate you and help.
5) lategame - as the time passes, there are more powerful tools available for you, especially at rnd. Things you really want - advanced energy gun (AEG) which is like taser, but also has third lethal option and recharges by itself over time, telescopic shield (will give you extra protection, basically like riot shield IIRC, but can be stored in your bag), magboots (so you dont get memed by breaches, also ask science guys for a "slime speed potion" , there is a chance they will give you one. Activate magboots and click with potion on them. Now any slowdown effects is removed, and you are always protected from slips and atmospheric problems (slime speed potion can be used on any other equipment like hardsuit or riot armor)). Different weapons, implants, tools and other useful stuff you can ask from rnd - there is too much to talk about, better play some science rounds to see what can be produced and how it works so you will know what to ask for.
6) bring at least two, better three pairs of cuffs with you. You never know.
7) as a detective you can use screwdriver on your revolver. Now it accepts lethal ammo from autolathe. Keep in mind - you need revolver to be empty from bullets before screwdrivering it, or it will just damage you in the process, and shooting with lethals has a chance of backfiring (instead of shooting, it will explode in your arm, it will damage you and force you to drop the gun) i do not recommend using it, if you need lethals as a detective (for example to fight wizard) better get a normal gun. But there is an option.
update security records and add notes to arrested crew, dont be lazy. You can not even imagine how many times i have freely walked out of brig because officers did not communicate and did not have a full picture of my crimes. And i tell you, i was worth if not execution, then at least perma.
9) use screwdriver on stunbaton - it will drop out powercell. Ask science for a best powercell possible, and you might get infinite charge stunbaton. Or at least a stunbaton with extended capacity. Just insert new powercell in it, no need to use tools.
Ultra, super, hyper capacity or bluespace powercell are what you are looking for. Charged slime core - infinite powercell.
Thats all for now