The assembly & painting of resin or white metal models requires essentially the same toolkit, most of which are pretty straightforward and probably already in your possession.
This section recommends a few specific pieces that will make working on your models faster and easier.
All of these should be readily available online or from good hobby/model shops - generally speaking there's no need to buy branded "official" versions - in several cases (eg. brass brush) the type available from typical discount stores will be more than adequate.
All tools & materials should be used with care and (where appropriate) in a well-ventilated area.
Scalpel or similar craft knife. Readily available with a variety of differently-profiled blades (10A are probably the most universally useful). Available in a range of different styles of handle, in fixed and retractable versions, and from several manufacturers. Swan Morton #3 handles are the most commonly used.
Used to trim sprue, clean mouldlines (when scraped perpendicular to the surface) and for a wide range of modelling tasks beyond just cutting out shapes in plastic or ply.
Needle files - buy the best quality set you can afford. White metal and resin will both clog the "teeth" of small files very quickly, but more expensive files will tend to allow easier cleaning (using a brass brush). If budget is restricted, buy a flat, half-round, and rat-tail (tapered full round) for most purposes.
Useful for cleaning up mouldines and adjusting the fit of all kinds of parts (eg. widening fitting slots).
Brass brush - readily available in multipacks both online and in poundshop-type outlets.
Extremely useful for cleaning thin flash and mouldlines from resin models - will remove loose material without damaging the model surface or removing detail.
Superthin cyano glue - we use this brand on a daily basis for working with resin, ply, and plastic, but any good brand of superglue should work.
Be extremely careful when working with these ultra-thin glues - it's VERY easy to stick your fingers together or, worse, to the model you're working on.
Liquid Accelerator - used with superglues for a faster cure and near-instant "grab". Again, use with caution.
We've used these liquid types for years in preference to the aerosol types - there's far less hazard involved from the possiblity of inhaling the fumes.
Applicator Bottle - available in a huge range of sizes and shapes. We use one of these with Liquid Accelerator for accurate placement at the joint or point of glueing.
Solvent Dispenser Pot - the safest and best way of working with plastic solvent cements, as used by all professional modelmakers (and colloquially known as a Tutty Pot)
Used with a brush for safe, measured dispensation of solvent, and far more stable than the small bottles that solvent is normally sold in.
Xuron Track Cutters - in this case, we recommend buying a specific tool rather than a generic one. These are, quite simply, the best side cutter pliers you can buy for the price, and will make short work of slotta tabs, excess white metal, and resin/plastic sprues and wells.
Spray Primer - we recommend Halfords own in-store brand (available in the UK) purely because we've used it for many years and have found it to be the only primer that consistently sticks to resin castings without issues.
Textured Paint - again, available from Halfords in the UK, but with many equivalent brands. Useful for adding extra detail to resin and plywood kits.
Steel Brush - used whenever heavy scoring is desirable on a model - for example, scoring random line patterns in styrene sheet to represent woodgrain. Also very useful for roughening resin or metal surfaces to be mated together for glueing.
Zona saw - fine, thin-bladed saw in a range of tooth-spacings, used to make clean, narrow cuts in resin or metal where minimal loss of material is required.
Engineer's square - available in many sizes. Almost indespensible for accurate assembly of right-angled joints.