1Collar 'Look at the collar first and how it fits,' says Sam the Tailor's Manu Melwani. 'It should sit perfectly on the neck.' 2Jacket 'The armhole shouldn't be too tight,' says Melwani. 'Check how it feels with the arms out and at your sides.' Ermenegildo Zegna shop manager Andy Cheng says: 'When your arms are down, there should be a little space for movement.' The sleeve length should just reach the base of your thumb, revealing a half inch to an inch of your shirt cuff. 3Trousers 'The crotch shouldn't be too low and should fit you snugly,' says Melwani. 'The trouser length should reach your shoes.' Cuffed or uncuffed is a matter of personal preference, but the latter can make you look taller. Cheng says: 'The waist band should sit comfortably across your stomach, as most men won't look good in high-waisted styles. If you have a big bottom or hips, go for double pleats which give you more room. If you're slimmer, opt for a flat front or single pleats.' 4Finishing 'Every brand or tailor has a unique style,' says Cheng. 'You can tell how good a tailor is in the finishing of the suit. Stitching is vital. Workmanship is also important. Handmade details are good but sophisticated machinery makes all the difference.' 5Overall Fit You should be able to move easily in your suit. 'At the end of the day, its all about individual preference - some men prefer slimmer-cut suits while others prefer more room,' says Cheng. Choosing fabric Many fabrics are 'Super 100', which is a popular term used by tailors, meaning the yarn has been twisted more than the usual 60-80 twists. A good fabric will spring back without wrinkling after it's squeezed. Slim men should opt for Italian fabrics, which are thinner and smoother (go for 160s or 180s, says Melwani). Larger men should go for super 120s and 150s. Be wary of fabrics that are too heavy: too much wool may mean that it doesn't fit you properly. Most people choose super 150s-180s. Trends Two-button suits with buttons placed higher, for a more modern look. Single-breasted suits are much more flattering, while 1950s styles are becoming popular. 'For autumn/winter, men go for heavier colours, while spring means lighter fabrics,' says Patrick Lee, senior menswear buyer at Lane Crawford.