A while ago I received a voucher which I couldn’t blow on mountainbiking as my shop didn’t accept these. It felt wrong to spend it on groceries and my queue of unpainted 40K Orks is just too long to add more models to it, so I got into pre-painted X-wing. Played a few intro games, got hooked on and decided to expand my fleet.
Much to my annoyance, after I’ve unpacked my first bomber, it turned out to be different colour to fighters from starter boxes. I know it’s something to do with blue box technology not working with certain colours back in the ‘70s but I. Just. Couldn’t. Give. A. Monkey’s! 
Rather than trying to repaint the odd ones (I find replicating someone else's paintjob tricky), I’ve decided to repaint everything. Despite over a decade of playing with toy soldiers I don’t like painting that much and definitely am not too good at it. Just trying to achieve a clean result, using basic techniques. Models are looked at from about one meter away most of the time, if something looks good from that distance, it's good enough for me. 
Pics are there just to give a rough idea what I'm on about, I'm utterly rubbish at taking them.
I’ll focus on the Empire ships only, terrorist Rebel ships don’t need that level of theme unification imho.
Paint stripping.
Disclaimer: Paint stripping is not exactly science, it can result in different results for different models. To avoid damaging your entire collection always work with small batches of models and keep an eye on the results.
A lot of people say there’s no need to strip the paint of x-wing models, I say different. No matter how thin the layer of paint is, in the end it may make a difference between a nicely painted model and a blob of paint. Besides, stripping pain off x-wing models is easy. I’ve found three ways to do it:
Dettol. Soak models for ca 15 minutes, then brush gently with a toothbrush, using Dettol itself or a diluted with warm water. Do not rinse with water (especially warm) until the paint is off, otherwise it’ll turn into a black sticky goo which is hard to remove. Also, no not leave to soak overnight, Dettol will melt the model to some extent. Oh and don’t use knock-off disinfectants (Tesco’s and the like), they don’t work, probably not enough pine oil in them. Pine oil has a very distinctive smell which lasts long especially on skin, use gloves when working with it. Dettol’s good to use as long as it’s clear, once it’s muddy get rid of it and use a fresh batch. Hell, I made it look complicated but it’s really not.
DOT brake liquid. Should Dettol fail for some reason try this one. Doesn’t matter if it’s DOT3 or DOT4 (you won’t be boiling it anyway), any brand from your local garage will do. Like with Dettol, soak for 15 minutes, then scrub with warm water and dish liquid using toothbrush. DOT can be re-used a few times, usually I’m getting three batches of models before it starts losing its potency. It doesn’t smell that bad, but it’s hygroscopic, so always seal the container and don’t touch it with bare hands as it’ll dry the skin pretty badly. Use gloves again. Sometimes, if one soak doesn’t do the trick, try a second one, maybe using fresh liquid. Not sure what’d happen to models left overnight, probably not worth trying.
Sodium hydroxide drain cleaner. Last resort, but sometimes necessary, especially for second hand models. The most important thing to remember here is this stuff can get pretty volatile heat-wise which is bad for plastic models. Never use brands with aluminium turnings, add too much substance or use boiling water, cos your models will simply melt. I wouldn’t use gel ones either, not sure how they may react with models before diluted . Put the models in a glass jar, sprinkle with roughly one tablespoon of stuff per 100ml of warm water, add water. Fumes are corrosive, so don’t inhale them, just cover the jar and leave for a while. Unlike Dettol and DOT, models can be left in caustic bath overnight, it actually may help. Rinse under running water a few times and use toothbrush. Drano has a tendency to chew thru cyan-acrylic glue, which is handy with those massive solar panels.
After every bath inspect the model thoroughly, being picky now can save you extra work at later stage. If there’s any residual paint left try to remove it by hand, preferably with a toothpick or some other sharp plastic tool – it’s less likely to scratch the model than a modelling knife.
Dettol-stripped second hand models. Some residual paint, which won't affect end result so not gonna bother removing it.
Priming.
Key to painting any model, it grants paint adherence and sets the theme for paintjob to come. There are many spray primers out there, the closer it is to final desired effect, the better. Rule of thumb is that dark colors are more forgiving when it comes to painting errors, but bright ones allow for more standing out effects. Oh and don’t bother with anything other than acrylic paints, at this skill level they’re by far the best. If you don't have a color which is close to your desired effect, use anything that's close enough and don't apply a full layer. In this case primer is mainly there for paint adherence, like on the pic below, where you can still see grey plastic from underneath.
On the other hand, no harm if the primer layer will be a wee bit thicker, like on the other side of this Interceptor.
Base layer.
Pick your colour and apply first layer on everything other than solar panels and cockpit canopy. Beginners should probably stay clear off white, yellow or red colours as these are usually more difficult to work with due to some pigment shenanigans. Either way, make sure your paint is watered down properly, it’s always better to apply two thin layers where needed, than one too thick.
Then paint the panels and cockpit, especially where they touch the frames. Being careful at this stage will save you extra work later, but don’t worry if some black paint will end up on the frame. Should this happen, try to wipe it with a finger before the paint dries, preferably back towards the panel, so you won’t smear black paint on larger surface. The less dark that spot will be, the less layers you’ll need later to cover it. Don’t worry about painting the middle of panels, they’ll get dirty during drybrushing anyway.
Drybrushing & final details.
Drybrushing is a form of highliting, only faster and requiring less skill. Grab a thick brush, dip it ever so slightly in paint and brush it against flat surface or palm of your hand until there’s hardly any paint left. Then do the same with the actual model. It takes some practice to get a right amount of paint, but again, it’s best to re-do it than over-do it. After it's done do the final touches - paint the panels, guns and glass, cover any imperfections, etc.
There. I hope it'll come in handy. Feel free to ask if you've any questions.
Nuln Oil. Probably the best of small Empire ships to use wash on, plenty of crevices there when looked down from player's perspective. Yet, I wasn't a happy bunny here, it's just too dark/dirty.
