By "mild deco" I mean less than 15 minutes of required total deco time, assuming one uses the same gas (air or nitrox 32) throughout the dive (stops included) and respects the maximum depth for this gas. An adequately experienced buddy team with low SACs can safely do that kind of dives with single tanks of adequate size.
This kind of diving is no sin (despite what some agencies use or used to say) and no rocket science (despite what some tech instructors or tech divers, prone to overkill, may say). But a recreational diver needs some additional learning and training, otherwise he/she may get badly injured.
For example, deco diving (even "mild") usually means 2 dives maximum per day (and quite often only 1 dive per day, it depends upon the severity of the dive) with a surface interval MUCH longer than 1 hour.
And there are some other things to know (e.g. understanding deco dive tables) that I won't mention or detail here. One cannot learn to dive by Internet only.
All decent dive computers that I know (at least Uwatec and Suunto) give all the information needed for mild deco diving with one gas (air or Nitrox 32, with no other gas for deco). And this is reliable, proven, information. These dive computers are routinely used for such mild deco diving by most French divers, including me.
But, because off-gassing is slower than on-gassing, it's safer to pad what computers say when it comes to surface intervals. Also it's a good practice to pad (add extra minutes) the shallower stops that your computer tells you to do. Bottom line : it's better to know what you are doing, even if you use a dive computer. A good course about deco will help for this.
A good Surface Air Consumption (SAC) and a proper gas (e.g. rule of thirds) and dive (depth and time) PLANNING are paramount because deco stops durations increase sort of exponentially (5 extra minutes of bottom time may represent 20 extra minutes of deco stops or even more) and if you don't take care you have to dramatically increase the duration of your stay underwater, thus risking OOA.
Also you need proper buoyancy control to accurately maintain your depth, notably (but not only) during the stops, and to master your speed of ascent. Proper weighting and buoyancy will reduce your SAC. Better reduce your SAC than breathe like a hoover because of all the heavy stuff you are carrying underwater.
Introductory courses for deco diving are CMAS **, or TDI Decompression Procedures, for example. In my opinion you'd better join such a course before doing deco dives. The problem with some agencies is that they use very heavy setups (twinset + stages, etc) for mild deco diving, as if there was nothing, regarding gear configurations, between no-deco diving and advanced Trimix.