Do you go into mobilization with your cities during war?

I do.

Just wondering how many of you during war time, devote the majority of your cities to producing military when at war. I will immediately change from structures to units if I get a DoW on me. Only exceptions are if I am close to finishing a wonder, my budget is negative, or the city in question is way too far away.

I remember CIVIII had a "Mobilization mode" where you turn it on and all you can produce is military stuff until the war is over, but you get a build discount on them. Kind of miss that feature, since I tend to do that now in CIV.

I at least do it for cities on the warfront and ones near those.

If defending, yes I usually start building units everywhere. If I'm attacking, I usually build all my units first then send them off in a big pack. While they are in transit, I'll be bolstering the infrastructure back home with things like universities or banks. Once the war starts I'll need to replace casualties so I do build some troops, but I'm trying to mostly build infrastructure and keep gold flowing so as to pay the maintenance. Tends to mean a mix of buildings/gold and/or units. Basically, it really depends but on defense if you get caught with your pants down you absolutely need to stop what you're doing and build units. On offense, not so much. You should have come up with a target number of units and built them before you got started. Then you need a way to pay teh maintenance from there cause usually a huge army will tank your economy once it gets out and starts moving across the map.

I try not to be forced into that, so I build units when I am ready and try to keep a standing army once my economy is moving. I think if you're churning out troops once a declaration of war is made, it's too late. Unless you're training reinforcements, and the economics of Civ V make that impractical sometimes...

Yeah, I like to have a steady flow of reinforcements. Typically they are newly researched units while the old units are at the front and usually cannon fodder. Of course, I upgrade the old units if I get the chance. The bigger your military, the more likely your opponent will offer you a sweet peace deal.

Also forgot to mention, when I am in an ally's war, and I have no interest in the cities. I typically just send mounted units/tanks to assist and pillage. No need to build units for another Civ's war.

It`s important to do. I find that if I don`t, there are not enough units when I need them and bang goes one of my cities.

I rarely declare war, but when I do, I usually go into a combo of buying and building units.

My wars are usually declared with a specific offensive purpose in mind (to punish for spying, to eliminate a certain city built in an annoying location, etc.), so the build order is planned in advance. A certain level of defense stays in my home territory (in addition to the usual garrisoned unit) while the newer units are sent out to get the job done ASAP. After Flight, I usually maintain a decent air force that can straddle both offensive and defensive duties.. so I'll build a building/wonder, then a bomber, then another building/wonder, and then another bomber, and so on..

I rarely build military units. If it happens, it should be done before you get war declared on you (and yes you should usually see that coming) because after that playing catch up is just gonna cost you way too much time.
In general, I build as few units as possible even during war. Cities should be building buildings, not useless things.

If I'm not next to #1 in soldiers I usually stay mid pack and let science naturally take me to #1 by upgrading what I have. If I grab Brandenburg Gate plus barracks armories and military academy the few units I make have nice promotions to keep me safe. 4 range battleships just destroy any unit attack long before they get close

I usually pop most units from the cap and the most productive city I have. The least productive need most of their time for buildings.

After I build HE, usually on the non-Cap most productive, sometimes on the cap, Cap is used more for some wonder attempts, and the other city is poping units alternating with buildings.

This way I keep a reasonable army at all times. Of course on some situations you want most of your cities poping units, for example when you get planes, or when you start doing a real army.

I like to focus on gold. $$$ = flexibility. I may not have a large standing army, and that may lull the AI into attacking me. In that case, I just purchase a handful of defensive units tailored to meet the force the AI sends. It's not hard to figure out the AI line of advance and then head 'em off at the point of your choosing. The AI will just throw units against your defenders until they deplete their forces, and then they'll sue for peace and maybe even give you a city in the process