The very first thing you must do is using a lint free cloth clean your Tank completely using Acrylic thinners (Isopropanol),(Avoid Tamiyas Acrylic Thinners because it is grossly overpriced )
NEXT, If you have any metal parts they will need painting with Metal Primer or the paint will not "take",
Your Tiger obviously being a WW2 German Vehicle will have been sprayed with a Red Oxide Primer so that should be your next job, (Automobile Accessory Shops are a good source of large sized Red Oxide Primer Rattle cans that will do a very good job for very little money),
Top coats can be painted with an Enamel finish but a water based acrylic top coat using either brush, rattle can or airbrush has the advantage of being relatively easy to remove and be repainted with a different camo style if you decide to update your Tank.
After that it is all about research,
Where did your Tiger serve ? Western Europe, Eastern Europe, North Africa/Southern Italy,
A Different camo scheme was used in each of these combat zones and within each zone different varieties of shades were used and in the winter in Eastern Europe an overall white with grey smudges were the order of the day,
It should be remembered that new and repaired German Armour was usually delivered from the factory in a Primer finish and forward workshops applied the topcoat,
This was not always the case and some Tanks were delivered complete with an applied top coat,
After issue to a crew they would load their Tank with Paint Blocks in different colours and if it was winter a bag of distemper as well as rags and using a combination of petrol, water, rags and the Tanks broom and Bucket would repaint the Tank as and when needed,
Bearing in mind how the Paint was applied at best it was crude and more often than not downright awful so unless your Tiger Is going to be a shelf queen you can be pretty basic and still be accurate
When that is done your thoughts will turn to the Tanks markings,
The real thing did not use Decals they used Stencils, (Much easier to apply over Zimmerit)
Our own Rad Schuhart will makeup a set to your specification or supply stock Stencils for very little money, BUT whatever you do DO NOT USE THE SUPPLIED HENG LONG /TAIGEN/TORRO Decals they are quite simply CR*P